sails on sailboats take advantage of which type of energy

Yachting Monthly

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Renewable energy afloat: the latest tech

• Sam Fortescue
• May 5, 2021

Sam Fortescue examines how renewable energy afloat is benefitting from technical developments in other sectors

Oceanvolt's electric drives feature a clean display that can tell you exactly how much electricity the system is consuming under power or generating under sail. Credit: Richard Langdon/Ocean Images

As the rest of the world grapples with decarbonisation, the sailing community is benefitting from the various technical developments made in other sectors, and now has more options to use renewable energy afloat.

It is now simpler to harvest and store power on board than ever before – no bad thing when you consider how many power-hungry gadgets fill a modern cruising yacht.

From Nespresso machines to electric winches, sailing consumers are reaping the rewards of the efficient electricity generation.

The core of renewable energy generation for boats remains wind, solar and hydrogeneration, but the last two of these are developing rapidly.

Meanwhile hydrogen is continuing to make inroads into the sailing market.

Jimmy Cornell’s Outremer 4.Zero has covered 1,500 miles from Tenerife to La Grande Motte using renewable energy, but the multihull’s hydro and solar capacity needs to increase before he can take it around the world. Credit: Gilles Foucras

It all comes down to how much power you need: a kilowatt-hour over the day to run the fridge and electronics (83Ah), or 50 times that for induction cooking, air-con and even electric propulsion.

Wind remains an important part of the mix, capable of adding up to 500Wh on a blustery day, but here the technology is more mature.

There may be small incremental improvements – quieter blades or more efficient power transfer.

‘There is not going to be a silver bullet in respect of renewable generation on yachts because the physics tell us that the existing technology is already very efficient,’ says Peter Anderson, MD of Eclectic Energy.

The D400 converts an industry-leading 36% of the kinetic energy in a 12-knot wind stream into electricity

Sam Fortescue is a freelance marine journalist and former magazine editor who sails a Sadler 34, which has taken his family from the Caribbean to the Baltic

‘For example, our D400 wind generator converts 36% of the kinetic energy in a 12-knot wind stream into electricity. The theoretical maximum (Betz Limit) is 59%, and the latest multi-megawatt commercial turbines achieve around 40% efficiency due to their scale.’

Nonetheless, he believes that a yacht can cruise entirely independently of fossil fuel, and he’s far from alone.

Jimmy Cornell’s Elcano Challenge aims to prove just that , aboard an electrically-powered Outremer catamaran.

True, he has just put the round-the-world voyage on hold, because the regenerating prop could not keep up with demand.

But he thinks the answer is to beef up hydro and solar capacity while trimming power use on board.

‘I am determined to continue my zero-emissions project once certain changes have been made,’ he says.

Solar panels have been with us for decades, and as the technology has matured, so they can produce more power from the same footprint.

Even a small panel putting out a few watts is enough to keep a lead-acid battery bank trickle charging when the boat’s on a swinging mooring. But some have already gone much further than that.

Renewable energy: solar developments

Catamaran builders, in particular, have been trying to capitalise on the extensive deck area of their boats by fitting solar panels.

Silent Yachts is ahead of the curve on this, with a 55ft cat whose 49m2 coachroof and hardtop are carpeted with 10kW of panels.

On a sunny Mediterranean day, that provides enough electricity to run all the boat’s systems and leave plenty for a few hours of electric propulsion.

Luxury cat brand Sunreef has developed cells that can be built into the actual fabric of the boat.

Solar cells, built into the structure of luxury Sunreef multihulls, vastly increase the solar power potential

‘They can be easily mounted anywhere on the yacht’s surfaces, including the hulls, mast, superstructure, bimini roof or bow terrace, vastly increasing the amount of solar power,’ says the brand’s Sara Smuczynska.

‘Sunreef Yachts is also the first company to develop a system to recover heat from the panels to heat up the yacht’s boiler.’

With panels in the topsides, decks and coachroof, up to 13kW can be installed on a Sunreef 50.

Monohulls are a different story. Gantries, guard wires and coachroofs can support panels of a few hundred watts – enough for basic systems.

But if you want to generate serious solar power for more ambitious green goals, then you need to think laterally.

That’s what Frenchman Alain Janet did when he launched SolarCloth – a business that sticks solar cells to your sails.

SolarCloth cells on the mainsail of the Spirit 44E produce 560W on a sunny day. Credit: Sam Fortescue

The advantage to this is obvious: the sails offer the largest surface area and their near-vertical alignment can suit the angle at which sunlight falls on them.

The cells are based on proven copper indium gallium selenide (CIGS) technology, capable of around 17% efficiency and very flexible.

Simply glued to the sailcloth in positions that won’t chafe on the spreaders under any reefing conditions, they are robust enough to withstand flogging, folding and all manner of abuse, as demonstrated during the 2016-17 Vendée Globe race by skipper Conrad Colman.

More recently, Spirit Yachts integrated the technology into its beautiful 44E performance cruiser , launched last autumn.

The Spirit 44E under sail. Credit: Richard Langdon/Ocean Images

On the Spirit, the cells were arranged in panels 30cm high and about 2m wide on either side of the mainsail, producing 560W on a sunny day.

Dr Vincent Argiro, who commissioned that boat, wanted a fast, energy-efficient design.

‘The stretch goal for the 44E was near total energy self-sufficiency,’ he says.

‘I envision plugging into shore power to be a rare event.’

Janet acknowledges the junction boxes and wires needed to connect the sail to the deck are clunky, but he is developing a sleeker solution.

Meanwhile, a new partnership with One Sails to produce the so-called PowerSails will give the idea fresh impetus and broader distribution.

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Janet says a PowerSail costs 50-60% more than a standard sail, while the same technology has also been used to add photovoltaics to biminis and awnings on cruising boats.

All this is based on silicon technology, where the record efficiency for an expensive six-junction cell is 39.2% in natural light.

But further down the line, emerging Perovskite technology could make photovoltaics lighter, cheaper and applicable to any surface by painting or printing.

Researchers at Imperial College, Cambridge University and China’s Soochow University calculate that it has the potential to eclipse silicon with up to 60% efficiency, once the issue of durability has been cracked.

Luca Bondi, technical director of Italian solar panel producer Solbian, says the future lies in the combination of silicon and Perovskite in the same cell.

‘Tandem cells made by crystalline silicon and Perovskite raised close to 30% efficiency,’ he says.

‘The increase in efficiency is important but not disruptive, thus I think we cannot say that we have a big step imminent, but an improvement of the already good existing solar cells.’

For those who dislike the look of solar panels, there is another option.

A printable film has been developed which is stuck on top of the solar panel to disguise it.

Finishes range from monotones that match your paint to a teak-effect that would allow you to add solar panels to decks.

Solbian supplies its monocrystalline panels with this so-called iSP mask, and Bondi says that it does very little to reduce their 24% efficiency.

www.onesails.com/uk www.solbian.eu

Hydro power on board

Sails are the most abundant generators of renewable energy on board, propelling tonnes of yacht at a brisk pace.

Converting just a fraction of the boat’s kinetic energy into electricity can yield plenty of power for the loss of less than one quarter of a knot.

Broadly speaking, there are two approaches.

The first is the well-established principle of hydrogeneration, where you lower a dedicated propeller into the sea that is turned by the passing water and used to drive an alternator.

Products in this space are typically mounted on the transom and deployed using a lanyard to generate power.

Custom deck mount for a Sail-Gen hydrogenerator

They include the Watt & Sea, which comes in 300W and 600W units, Eclectic Energy’s SailGen and Italy’s 600W Swi-Tec.

More recently, regeneration has emerged as an alternative. It harnesses the same principle but uses your auxiliary propeller to generate the power, so no need for a bulky transom unit or the braking effect of a second prop in the water.

There are retrofit options available from the likes of Holland’s Bell Marine, but it is relatively expensive to install, so the more common option at the moment is to fit a new hybrid propulsion system – either diesel-electric or battery-electric.

If your engine needs replacing it’s worth considering.

However you configure it, hydro can be a very efficient way to generate power, especially at scale.

A dedicated propeller of a hydrogenerator is optimised in pitch and diameter for maximum torque

The 350ft Dynarig yacht Black Pearl is able to sail across the Atlantic without burning any fossil fuel – its twin props regenerate hundreds of kW of power.

Cruising yachts, on the other hand, will struggle to generate even a kW, and typical output at five knots doesn’t exceed 100W.

This is because the power out is a cubic function of boat speed, linked to water past the prop, so even a small speed increase hugely increases yield.

Nudge up just a little to seven or eight knots and you can get a more manly 300W from regeneration.

Dedicated hydrogenerators are more efficient because their props are pitched and sized according to your boat’s cruising speed.

With regeneration, your main prop will be optimised just for propulsion. Only a variable pitch prop can excel at both tasks.

Under sail in regeneration mode, the three-masted Black Pearl is capable of crossing the Atlantic without burning any fossil fuel. Credit: Tom Van Oosanen

That is what Finland’s Oceanvolt has achieved with the Servoprop – whose pitch adjusts electronically in real time to extract the greatest possible power from regeneration.

The team behind it claims that it can boost electricity output nearly threefold compared to a fixed prop.

Indeed, at seven to eight knots it produced 1kW of power.

There again, at five knots, output falls to around 200W.

It all depends on how much power you need.

For house loads, 200-300W should be more than enough, but for electric propulsion you’ll need far more.

Servoprop comes as a complete saildrive system with the option of either a 15kW or a 10kW motor.

But electric propulsion rival Torqeedo is sceptical about variable pitch systems on small motors.

‘It’s not possible to get much more than 300-400W because the physics makes it tough to adapt the pitch of the prop and to take care of the waves,’ says sales director Phillip Goethe.

‘When your speed through the water is changing often – from stalled to surfing, it is very hard to have the optimum pitch.’

Instead, Torqeedo’s notion is to spec a fixed-pitch propeller that strikes a compromise between propulsion and regeneration.

‘Perhaps you lose 2% [in propulsion], but gain two digits in hydrogeneration efficiency,’ says Goethe.

‘But for cruising applications, it doesn’t need to be optimised for propulsion above seven knots.’

Oceanvolt 15SP: from €46,660 ex-VAT www.oceanvolt.com Torqeedo: www.torqeedo.com Hybrid Marine: from £14,980 ex-VAT for a 30hp engine and 10kW motor. www.hybrid-marine.co.uk

The cost of hydrogenerators

Watt & Sea: £3,504.10 (300W) www.wattandsea.com SailGen: £2,464.69 www.eclectic-energy.co.uk Swi-Tec: £3,080 www.swi-tec.com

Hybrid options for renewable energy onboard

Isle of Wight-based Hybrid Marine specialises in diesel-electric parallel hybrid systems built around new Beta and Yanmar engines.

They can take advantage of regeneration and allow limited manoeuvring using the electric motor, with the diesel for longer passages.

Hybrid Marine specialises in diesel-electric parallel hybrid systems

‘Retrofits are tricky. It takes a lot of work to reliably convert an engine and means it has to be removed to make the conversion. Accumulated costs work out close to a new system,’ says MD Graeme Hawksley.

Hydrogen propulsion

Hydrogen fuel cells can be used either to provide small amounts of electricity to charge a battery, or at larger scale to power an electric drivetrain.

Either way, they can be emissions-free if they use hydrogen produced using renewable energy.

Hydrogen is attractive because it is three times as energy dense as diesel, but being a gas in ambient conditions, it must be stored under tremendous pressure – up to 350 bar on boats, requiring voluminous storage cylinders.

Efoy leads the market for marinised low-power fuel cells, with a 40W and 75W unit available.

Phil Sharp with the Genevos hydrogen power module

It burns methanol supplied in 5lt and 10lt ‘cartridges’ that are available from distributors across Europe.

You can simply clip the output wires to a suitable charging point on your battery system, but for optimum efficiency, Efoy also supplies its own Lithium batteries in 70 and 105aH capacities.

Though Efoy doesn’t quantify the benefit, it describes this combination of fuel cell and battery as ‘particularly efficient’ by avoiding unnecessary charging cycles.

A 10lt canister yields just over 11.1kWh of usable power – enough for four weeks of typical use, according to Efoy.

Beyond that there is a bit of a void in the market until you reach a power output of 15kW, where the purpose is to supply an electric motor for propulsion, as well as covering the boat’s domestic load.

French company Genevos has already started selling a 15kW fuel cell tested by singlehanded racer Phil Sharp during a Solitaire du Figaro campaign.

‘We’re going to see quite a lot of private projects as retrofits in coming years, and by 2025, there’ll be production boats with hydrogen energy systems,’ he says.

That’s despite typical costs of around €100,000 to supply and install a system.

French firm EOD is developing plans for futuristic looking floating hydrogen fuel stations that actually generate H2 from seawater

Rival Energy Observer Developments (EOD) is designing fuel cells in the 60kW to 1MW range for larger vessels.

It stems from a project that demonstrated how solar and wind power could be harnessed to make hydrogen from seawater on a round-the-world prototype.

Other than the sheer cost, the current stumbling block is that hydrogen gas is not yet widely available in ports or marinas.

‘However, we’re going to see much wider access to hydrogen in five years’ time,’ promises Sharp.

EOD is developing futuristic-looking hydrogen fuelling stations that float in a corner of the marina and generate hydrogen from seawater using green mains electricity.

And British firm Fuel Cell Systems says its first marina hydrogen pumps should be installed in the south of France this summer.

‘Although the UK will be very slow to pick it up in my experience,’ cautions CEO Tom Sperrey.

Efoy Fuel Cell 80: £2,195 Efoy 5lt methanol £37.80 Efoy 10lt methanol £53.40

www.fuelcellsystems.co.uk

Battery tech

Lithium is still the performance choice for storing renewable energy on board.

Advances in chemistry and design driven by the automotive sector are making it possible to store more energy in the same footprint.

So the capacity of the BMW i3 battery that Torqeedo offers has risen from 30kWh to 40kWh over five years.

Oceanvolt lithium batteries on a Feeling 32

Promising technologies have been demonstrated in the lab. California’s QuantumScope has developed a stable battery that uses solid lithium as the anode, and offers four times the energy density of current lithium batteries plus lightning-fast recharge speeds.

Other approaches use graphene, salt, aluminium and even ceramic, as well as solid electrolytes.

‘The technological development of batteries is really fast,’ says Oceanvolt’s head of R&D Marko Mäki.

‘We believe that in the future, the combination of battery price, capacity and safety will only improve.’

Expect performance gains of 5-10% per year.

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What Energy Does a Sailboat Use? Discover The Secrets Here

Sailboats have been around for centuries, used by ancient civilizations to traverse oceans and explore new lands.

But what type of energy do sailboats use? To find out, let us embark on a journey exploring the many facets of sailboats from the different types of boats to the physics of sailing to the advantages and disadvantages of using wind energy.

By the end of this article, you’ll have a better understanding of how sailboats harness wind energy and the alternative forms of energy available for sailboats today .

So, let’s get started!

Table of Contents

Short Answer

A sailboat typically uses wind energy to propel the boat forward.

The sails capture the wind and use it to move the boat in the desired direction.

Additionally, the sailboat may also use auxiliary power in the form of an electric motor or gasoline engine to supplement the wind energy.

Finally, the energy provided by the crew’s rowing or paddling is also commonly used to move a sailboat.

History of Sailboats

Sailboats have a long and fascinating history, dating back to ancient times.

The earliest known sailboats were used by the Phoenicians in the Mediterranean Sea over 3,000 years ago.

These ancient vessels were powered by a single mast and a large sail made from animal hide or woven fibers.

They were used to transport goods and people across the sea, and were even used in naval battles.

The technology of sailing gradually spread throughout the world, and by the 16th century, sailboats were used for exploration and trade.

The Age of Discovery saw the invention of larger and more sophisticated vessels with multiple masts and multiple sails.

These vessels allowed for longer and more ambitious voyages, and opened up the possibility of global exploration.

Today, sailboats are still a popular way to explore the open waters, and are seen as a symbol of freedom and adventure.

They are also an environmentally friendly form of transportation, as they are powered by clean and renewable energy sources.

Whether you’re looking for a leisurely sail around a lake or an ambitious journey across the open ocean, sailboats can provide you with an unforgettable experience.

Types of Sailboats

When it comes to sailboats, there are many different types to choose from.

From basic dinghies to luxury yachts, there are numerous options available depending on what kind of sailing experience you are looking for.

The main categories of sailboats include dinghies, keelboats, catamarans, and trimarans.

Dinghies are the most common type of sailboat and are typically used for recreational sailing.

They are usually 10-15 feet in length and have a single sail.

These boats are light, easy to handle, and great for beginners.

Keelboats are larger vessels that range from 20-50 feet in length and are usually used for racing or cruising.

They have a fixed keel, or fin, underneath the hull that helps keep them stable in the water.

Catamarans and trimarans are two- and three-hulled sailboats, respectively.

They are typically used for racing and cruising, and are known for their stability and speed.

Catamarans are becoming increasingly popular due to their spacious cabins and large decks.

No matter what type of sailboat you choose, one thing is for certain: they all use wind energy to move through the water. The sails on these boats are designed to capture the wind, which in turn propels the boat forward. Some sailboats also have small engines that can be powered by fossil fuels, allowing them to make longer journeys and move against the wind if necessary.

The Physics of Sailing

Sailing is one of the oldest forms of transportation, and it still remains a popular way to explore the open waters today.

But how does it work? What energy does a sailboat use to move through the water?

The answer lies in the physics of sailing.

When the wind blows, it pushes against the sails of the boat, creating an aerodynamic force that propels it forward.

This is known as the Bernoulli effect, which states that as the wind passes over the sails, the sails shape creates a low-pressure area on one side and a high-pressure area on the other.

The low-pressure area pulls the sailboat forward, while the high-pressure area pushes it back.

In essence, this is the same principle behind an airplanes wings.

The sails of a sailboat are designed to capture the wind and maximize the Bernoulli effect.

The sails are angled in such a way that they capture as much wind as possible, and the shape of the sail is designed to maximize the aerodynamic force.

The sails are also adjustable, allowing the sailor to adjust the angle of the sail to catch the most wind possible.

In addition to the wind, some sailboats also have small engines that are powered by fossil fuels, allowing them to move against the wind if necessary.

These engines are usually used for longer journeys, or to move quickly when the wind is not in the boats favor.

Sailing is a unique form of transportation, and it relies on the power of the wind to move the boat forward.

But it is also a renewable form of energy, and it has been used for centuries.

So the next time youre out on the open waters, take a moment to appreciate the physics of sailing and the renewable energy that powers your journey.

How Sailboats Harness Wind Energy

When it comes to sailboats, harnessing wind energy is essential for movement.

This is done by utilizing the boats sails, which are designed to catch the wind and propel the boat forward.

The sails, which are typically made from canvas or synthetic fibers, are positioned in a way that allows them to best capture the wind.

Depending on the design and size of the boat, there can be one, two, or even three sails.

The sails can be adjusted to best capture the wind, which is known as trimming the sails.

With the right amount of wind, a sailboat can achieve speeds up to 15 knots or more!

In addition to the sails, the design of the sailboat itself plays an important role in how efficiently it harnesses wind energy.

The shape of the boat and the placement of the sails are important factors that determine how much energy can be captured from the wind.

The position of the keel, the weight of the boat, and the size and shape of the rudder also all play a role in how efficiently the boat moves through the water.

Finally, the skill of the sailor is also essential for a sailboat to move effectively.

A sailor must be able to read the wind, adjust the sails, and use the rudder to steer the boat in the right direction.

With the right combination of skill and equipment, a sailboat can make the most of the wind and move efficiently through the water.

Advantages of Using Wind Energy

Wind energy is an incredibly efficient and renewable source of power, making it a great choice for sailboats.

Not only does it offer a clean and eco-friendly option for powering a boat, but it also helps to reduce the boats fuel consumption and can save money in the long run.

Wind energy can also be used to propel the boat forward even in light winds, allowing it to make long journeys and explore more remote areas.

Wind energy is also much quieter and more pleasant than the roar of a diesel engine, making it a great choice for those who want to enjoy the peacefulness of sailing or who are looking to avoid disturbing the wildlife.

Additionally, it is a great way to get the most out of a sailboats design as the sails can be adjusted to make the most of the wind.

Disadvantages of Using Wind Energy

Although wind energy is a renewable and environmentally friendly form of energy, it has a few disadvantages compared to other forms of energy.

First, wind is inconsistent and unreliable, and can be unpredictable.

This means that a sailboat needs to be prepared to go with the flow, as any sudden changes in wind direction or speed can cause the boat to turn unexpectedly or lose speed.

This can be dangerous for sailors who are unprepared for sudden changes.

Additionally, the amount of energy that can be gained from the wind is limited, meaning that sailboats typically have a lower top speed than other forms of transportation.

Finally, wind energy can be difficult to harness and control, as the sails must be adjusted continuously to ensure that the boat is taking full advantage of the wind.

Alternative Forms of Energy for Sailboats

Sailboats have been around for centuries, and have been used to explore the open waters and transport goods for just as long.

The traditional source of energy used to propel them forward was the wind, which was harnessed by the boat’s sails and used to travel through the water.

However, in recent years, sailboats have also begun to make use of other forms of energy.

One of the most popular alternative energies used by sailboats is solar power.

Solar panels can be installed on the boat, allowing them to collect the sun’s energy.

This energy can then be used to power the boat, either directly or by charging batteries that can then be used to power the boat.

This is a great way to maintain an eco-friendly lifestyle while still being able to explore the open waters.

Another alternative energy source for sailboats is biofuel.

This fuel is made from renewable sources, such as vegetable oils or animal fats, and is a much cleaner source of energy than traditional fossil fuels.

Biofuel can be used to power small engines on the boat, allowing them to travel longer distances and make long journeys.

Finally, some sailboats also make use of electric or hybrid engines.

These engines are powered by electricity, either from batteries or from a generator, and can be used to supplement the wind power when necessary.

This can help to make sailing trips faster, more efficient, and more eco-friendly.

Although the traditional source of energy for sailboats is still the wind, these alternative forms of energy are becoming increasingly popular.

They allow sailors to explore the open waters while still maintaining an eco-friendly lifestyle, and can even make sailing trips faster and more efficient.

So, the next time you’re planning a sailing trip, make sure to consider all the energy sources available to you.

Final Thoughts

Sailboats are a great way to experience the open waters, and they have been used for centuries.

They use wind energy to move through the water, which is a renewable and environmentally friendly form of transportation.

You can find out more about the different types of sailboats, the physics behind sailing, and how sailboats harness wind energy by researching online.

With this knowledge, you can make an informed decision on whether sailboats are the right choice for your next adventure!

James Frami

At the age of 15, he and four other friends from his neighborhood constructed their first boat. He has been sailing for almost 30 years and has a wealth of knowledge that he wants to share with others.

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What Supplies Energy To Move A Sailboat? (Multiple Things)

Sailing is a lot of fun and there is nothing like it. When you are gliding across the water with the wind in your face, you get a feeling of surrealness. I love it more every time I am out there.

The force of wind and water on your boat’s sails and keel will supply energy to move your boat forward. The keel keeps your boat from drifting to the side and the sails give your boat forward motion. Different sails will work better in certain wind conditions for more energy.

Although wind and water give your sailboat power, let’s dive deeper into how they do this and how you can get more energy. First, let’s talk about wind types.

Wind Types And How They Affect Boat Movement

Sailing is one of the best experiences out there. The wind will become your best friend when you start sailing. When the wind is non-existent, you will be very upset at times, but just remember, the wind always comes back. There is a lot to the wind besides just wind. There are multiple types and certain amounts that are better than others. This section will talk about wind and what it is.

There are multiple types of wind when it comes to sailing. You have true wind (the speed of the wind when not moving). This is what the weatherman tells you on channel 5. If you go stand outside right now and don’t move, do you feel any breeze? If you do, then that is the true wind you are feeling.

Then there is apparent wind (the wind experienced while in motion). Imagine you are running into 10 mph of wind straight on, the wind feels so strong when you do this. If you stop running, the wind doesn’t feel as strong does it? When you are running and the wind feels way more powerful than 10 miles an hour, that is the apparent wind. Think of it as two strong forces going against each other.

This is what really affects your boat when sailing upwind. The apparent wind hitting your sails and boat will create a force that moves your boat forward. This will create more speed when sailing upwind. I love sailing upwind because it feels more intense. The wind is in your face, the boat is heeling over, and it just feels fast.

If you ever turn downwind after sailing upwind for a while, it is kind of disappointing. The big breeze in your face goes away, the heel of your boat will decrease, and it just won’t feel fast. The truth is your speed may still be good, but it’s harder to tell when traveling with the wind.

It’s clear that wind is a huge part of moving a sailboat. There are other parts that help move this boat forward though. Let’s look at keels next, and how they are helping with energy.

What Is The Purpose of a Keel? The Different Forces

The main purpose of the keel is to keep your boat balanced while sailing. If your boat is well-balanced, it will have more speed through the water. It will also help prevent your boat from drifting to the side when the wind is blowing.

Keels carry the ballast, which is a large weight. They can weigh anywhere from 100 pounds to 5000 pounds and sometimes even more. They are an essential part of your boat and sailing without one would be nearly impossible.

Take a look at the diagram below. It shows the wind pushing on the sails and how the force of the keel keeps the boat steady and on course.

As you can see from the images above, the sails are being pushed out causing the keel to be forced in the opposite direction. This is where the heeling would start to happen. The wind is pushing the sails to the starboard side and gives them lift, while the keel pushes in the opposite direction against the water. These two opposite direction forces, drive the boat forward because of its design.

The diagram below is of the same boat but with an aft view. This way you can see how the keel is pushed in the opposite direction causing the boat to heel. The keel pushes against the water or current to create its balancing force. The force of the keel against the water and the wind force against the sail sends your boat forward.

A side note to mention when talking about the keel and the water is current. The current can have an effect of energy on the boat’s motion. A current against the boat will definitely affect its energy. The more the current the harder it will be to sail into it. Sailing with the current is less drag making it easier to maintain the boat’s momentum.

As I mentioned before, all of these different forces are what drive the boat forward. The amount of force from the wind and water is what will allow you to have different speeds across the water. I won’t go into a discussion of a bunch of different sailing directions but I will mention one with a lot of speed. The beam reach is going to have a lot of force giving you good heel and speed.

Beam Reach Sailing

We talked about how sailing upwind is going to be better speed than downwind, but what about a beam reach?

Beam reach sailing is probably going to be your fastest point of sail. The boat is receiving the most force from the wind and water at this point, forcing your boat forward at optimal speeds.

When you are in a beam reach you can expect a good heel of the boat. The wind is lifting and filling your sails while the water is pushing against your keel and rudder.

These two forces working against/ together will create the best speed for the boat. See the Beam Reach area in the image below:

If you were going straight downwind, your sails would be full but it would be more of a pulling motion from your sails. You will not have that lift and help from the water against the keel and rudder. Think of it like this;

When you are in a beam reach the sails will fill up with wind and slightly lift the boat creating less drag. Now when you go downwind the sails fill up and just pull your boat along with more drag, not lifting the boat.

There is one more thing that supplies energy to move your boat and that is the boat’s motor. Let’s talk about that briefly since we all know how a motor works.

Motors And How They Move Sailboats

It’s pretty obvious how a motor moves a sailboat. It moves it like it moves all other boats, by propulsion. I won’t go into too much detail here since we all know how a boat motor works. There are a few things I want to mention though.

There are outboard and inboard motors. The outboard is mounted on the back of the transom and the inboard is inside the hull somewhere. They both have props that will propel the boat forward when in use. The speed of your boat will depend on the size of the motor and the size of the boat. If you are motor sailing you don’t need to go that fast. Motors are mostly for getting in and out of port, or moments when there is no wind. With sailing, you should never be in a hurry to go anywhere. Unless of course, it’s a race.

Just about every cabin-sized sailboat has a motor. Trying to back out of a slip with a 30ft sailboat with no motor would be almost impossible. They are a great help for navigating docks and ports. The only downside is they do require some type of fuel or electricity. It’s not a huge downside since you won’t be using it much, but the natural energy from wind and water is much better.

If you want to find out more about motors and how to attach them to your sailboat, check this article out!

In Conclusion

The wind, water, and keel supply energy and forces to move the sailboat forward. The engine is an exception in some cases, but the wind, water, and keel are your main components. The wind pushes against the sail and the sail harnesses the wind. While the sail works, the keel is below the water’s surface pushing against the water/current creating an opposite force. These forces compound together shooting your boat forward in motion. The more these two forces push the faster the boat will go.

Boatlifehq owner and author/editor of this article.

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Wind ships ahead: Technology pulling more power from sails

Wind has never been entirely dead. But now that we have realized the ecological consequences of burning fossil fuels, and the International Maritime Organization (IMO) has imposed binding global emission restrictions, wind-assisted shipping is attracting attention again. Two French companies have shown how to use aerospace technology to double the propulsion power of wind.

The physical principle is the same one humans have used on sailing boats since eons ago: The wind hits the leading edge of the sail and splits into two flows that are redirected and travel at different speeds toward the trailing edge, causing a pressure difference that simultaneously pulls and pushes the sail and the craft forward. What has changed is the efficiency. Advanced science has doubled the amount of propulsion power per square meter of sail surface, said Marc Van Peteghem, naval architect and co-founder of VPLP Design. Together with the French engineering firm CNIM, VPLP has developed a new wing-sail concept they call OceanWings, based on an existing VPLP idea.

From plane to ship  In recent years, a number of attempts have been made to combine the propulsion principle of traditional sailing boats with the aerodynamic efficiency of an airplane wing with the trailing edge flap extended for taking off or landing. “There is a slot between the two elements of the wing, and the air going through the slot accelerates the flow and pushes the turbulence toward the trailing edge,” Van Peteghem said.

In the case of an airplane, the thrust created by the engine moves the craft against the air, causing the airflow to divide at the wings and generate the uplift force. The principle is reversed in the case of a sailing boat: The wind hits the sail rather than the sail being pushed against the wind. The physics is the same, however. Transferring the two-part concept of the plane wing and flap to a sailing boat results in a wing sail, which consists of two vertical, more or less symmetric, parallel “blades” or “wings” with a narrow gap between them. The gap splits and redirects the airflow again, reinforcing the aerodynamic effect and producing additional thrust.

The concept has been the subject of various experimental designs for some time, including inflatable as well as rigid or segmented hard-shell prototypes. While significant efficiency improvements have been achieved, controlling and reefing the sail has been complicated, requiring exceptional skill and experience. 

Automated handling  The OceanWings design takes a slightly different approach. Each of the two straight blades has a mast of its own and consists of several horizontal segments, the “body” of each segment formed by a flexible fabric. Raising or lowering these segments along the mast allows the surface of the sail to be increased or reduced, or “reefed,” and lowering all segments to the lowermost position “furls” the sail entirely. The angle between the two parts of the sail can be adjusted as desired; each blade can rotate 360 degrees around its mast.

The second key element of the OceanWings concept is that the complications associated with finding the proper position for the given wind condition and desired direction of travel are eliminated, as the entire wing sail is fully computer controlled. All the operator needs to do is choose the heading, and the computer will position the two parts of the sail to achieve optimum thrust, adjusting the camber and twist as required. The sail has been tested successfully on VPLP yachts — including the hydrogen fuel-cell catamaran Energy Observer launched in 2017 — and is commercially available. According to Van Peteghem, OceanWings sails can reduce fuel consumption by 18 to 42 percent, depending on ship type, route and sail arrangement.

But VPLP has far more ambitious goals than yachting. “It is time to transfer the technology we have developed in the yachting industry to the shipping industry,” Van Peteghem said. “A wing sail could be installed on any ship where it is freely exposed to the wind.”

His company advertises its OceanWings wind propulsion technology as an auxiliary source of propulsion power for merchant ships to help achieve the desired EEDI. Looking further into the future, hybrid vessels combining an eco-friendly engine fuel with wing sails and solar panels on board could one day be an option for GHG-neutral, sustainable shipping. Of course, not every sea route has the right wind conditions for such a solution, but on those routes that do, taking advantage of the wind as an inexhaustible energy source certainly makes ecological and economic sense.

Certification services  Once a new wind propulsion concept enters the commercial stage, it is the responsibility of class to ensure the system is safe and reliable, Van Peteghem said. Projects like the recent successful rotor sail installations by the MariGreen consortium and Norsepower, both with DNV GL certification, as well as OceanWings and other sail types have delivered encouraging results. To support these efforts, DNV GL published its new class notation “Wind-assisted propulsion systems” in 2019. What the industry needs now is substantial capital investments in these proven wind technologies so they can enter the mainstream and unfold their carbon abatement and fuel-saving potential.

Hasso Hoffmeister is senior principal engineer at DNV GL.

By Professional Mariner Staff

Sail Types: A Comprehensive Guide to 8 Types of Sails

Sailboats come in all shapes and sizes. And that means there are many types of sails on the market! For those who might not know, sails are made of canvas and use wind power to propel sailboats through the water.

Understandably, different sails are required for different types of sailboats . And sailboats are categorized by the number of hulls they have. Monohulls have a single-hull design, catamarans have two hulls, and trimarans have three. Generally, sailors use catamarans for upwind sailing (but they can be used to sail downwind in certain conditions). 

The type of sail you'll need for your sailboat depends on the kind of sailboat you have. Additionally, sails are highly dependent on the wind and weather conditions. Therefore, it's always a good idea to have different types of sails on board to navigate the ever-changing weather conditions. 

8 Types of Sails for Sailboats

As mentioned, you should carry multiple sails when sailing to prepare for various weather conditions. Here's a brief overview of the types of sails for sailboats: 

1. Mainsails

The mainsail is the largest and most important sail. Therefore, it's probably the first sail to come to mind when you think of camping. Typically, it's situated directly behind the mast — connected to the boom — and uses wind energy to move the vessel. The mainsail plays a significant role in tacking and gybing, making it essential for any voyage. 

Since the mainsail is a larger sail, it doesn't require wind to propel it forward. And the fact that it can be moved by moving the boom makes it uber-easy to operate. 

Learn More About Sailing

2. Headsail

The headsail often accompanies the mainsail, though it is smaller in size. Regardless of your sailboat type, the headsail is positioned at the front of the mast – over the sailboat's bow. 

Because headsails are small, they are helpful when navigating through windy conditions. Smaller sails catch less wind, preventing them from propelling your boat as strongly as larger sails. Additionally, headsails help lift, balance, and protect the vessel from inclement weather conditions.

While the term 'headsail' refers to any sail in front of the mast, the jib is the most common type of headsail. (And when a jib is so large that it overlaps the mast, it's called a genoa.)

Learn More About Sailboats

3. Genoa 

The genoa is a large sail that attaches to the front of the forestay. (In this instance, it's similar to a headsail.) However, the genoa is larger than the headsail and overlaps the mainsail partially or completely to help the boat go faster. 

Genoa sails are useful when sailing through light or medium wind. You can also use it when the wind comes directly from the rear. If you use a Genoa sail during high winds, you'll probably start sailing too quickly and put yourself and your boat at risk. 

4. Spinnaker

The spinnaker is a large and whimsical (often colorful) sail. Spinnaker sails are usually symmetrical, allowing them to reach different points of sail. Generally, these are lighter sails and don't cover the mast like the genoa. 

Because spinnaker sails are on the larger side, you have to be incredibly careful with them. Don't use them in rough conditions. Instead, save them for sailing in low winds and calm seas.

5. Gennaker

As the name suggests, the Gennaker sail combines a spinnaker and a Genoa sail. They are as large as the spinnaker, although they're not symmetrical.

They come in handy whenever the wind changes from a pure dead run to a reaching point of sail, as sailors can navigate various wind types with the same sail. It's still only meant for lighter and milder winds, but it's more versatile than the spinnaker and genoa. 

6. Light Air Sails

Light air sails are useful in calmer conditions when the headsail and mainsail alone aren't cutting it. They include:

• Code Zero : A code zero sail is a gennaker sail ideal for sailing in light to mild winds. It's designed to create lift and boost boat speed whenever regular sails don't generate enough power. For that reason, many racers and cruisers use code zero sails to improve performance and gain control in various situations.   
• Windseeker : This small, special sail is reserved for no wind or light wind. Essentially, it helps boats remain maneuverable in extremely calm conditions. And for that reason, it's valuable to long-distance sailors. 

7. Storm Jib

Storm jibs can be used as a headsail whenever the weather is particularly rough and windy. Because it functions as a safety seal, it prevents boats from capsizing by reducing the sail area exposed to the wind. Therefore, it's a necessary sail for every sailor. 

Read Next: Boating in Inclement Weather

During strong winds and storms, sailors can raise a trysail — a small, triangular sail near the boat's stern — for better control and stability. Generally, sailors do this whenever the mainsail becomes too large and challenging to maneuver.  

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• Systems & Propulsion

Electric and Hybrid Propulsion for Sailboats

Practical sailor looks at the players in the developing field of electric auxiliary engines.

How soon will electric auxiliary propulsion be available to everyman? That depends on whom you ask. Opinions differ widely not just on what type of drive system might surge to the forefront, but even on whether the concept itself is viable. While a handful of companies forge ahead, notably Glacier Bay and Electric Marine Propulsion on this side of the Atlantic, some expected participants are waiting on the sidelines.

Photos courtesy of Manufacturers

One of the big issues that divides promoters and detractors alike is whether the appropriate way to go in a sailboat is with a pure diesel-electric drive train, with a hybrid electric drive with a diesel generator as back-up, or as a pure electric drive with regeneration capability. We’ll take a look at these and other options later in this article. For now, the short answer is that no single approach suits every sailor all the time.

Simply put, in the diesel-electric system, the electric motor runs only when the diesel-driven generator is running. Such arrangements have long been employed in railway locomotives, submarines, and commercial vessels of many types. In the hybrid system, a large bank of batteries provides the energy for the electric motor and the diesel generator recharges the batteries. On the face of it, the hybrid system offers a certain degree of redundancy in that, assuming the batteries are kept well charged, the boat has a measure of emergency power should the generator fail at an inopportune moment. The hybrid also is capable of recharging its batteries when sailing: Driven by the turning propeller, the motor becomes a generator.

Each of these approaches has its strengths and weaknesses, and while we’ll leave it to their developers to work out the technical issues, we would like to urge anyone contemplating installing an electric drive, or purchasing a boat that has one, to first look very closely at how they expect to use the boat. There’s more entrained in the choice than in picking a flavor at Baskin-Robbins. More on this later.

Among the electric drives currently available in one form or another, or as components, the big variable is operating voltage. Motors are available that run on 24, 36, 48, 72, and 144 volts, and, in the case of Glacier Bay’s diesel-electric system with Ossa Powerlite technology, 240-volt DC. Each supplier will discourse at length on the merits of their voltage choice, but an inconvenient fact haunts the entire field: High-voltage DC is deadly, potentially more so in some circumstances than AC.

While neither form of high-voltage is “safe,” we have a lot more experience with AC aboard recreational vessels than with high-voltage DC. An extensive body of knowledge exists on which to base AC installations so as to make them safe as well as reliable. High-voltage DC is used in a variety of marine and non-marine commercial applications, but these installations are well protected from access by untrained operators.

What voltage constitutes high voltage? That, again, depends on whom you talk to. The American Boat & Yacht Council (ABYC), which sets voluntary standards for the marine industry, defines it as 50 volts and above. Prompted by rapid adoption of high-voltage services in small commercial craft and bigger yachts, though not specifically in propulsion systems, the ABYC is in the process of drawing up guidelines for voltages higher than the 48 volts covered by existing standards.

An absence of standards might not deter individuals from installing an electric drive, but it might impede widespread adoption of the technology. If a surveyor can’t state in an insurance survey that a boat is built according to ABYC standards, that could affect its insurability.

Jim Nolan, who manages the underwriting department for BoatUS, said the company has no clear cut guidance regarding insuring boats with electric propulsion. Each boat is dealt with on a case-by-case basis. A new boat with a factory-installed system would be a good deal easier to underwrite than a one-off or do-it-yourself project, especially in the absence of a standard practice. Lagoon Catamarans’ 72-volt-DC hybrid system, for instance, has qualified for the European standard (CE) certification on the strength of following industrial standards that apply to such applications as fork-lift trucks. Anyone contemplating an electric drive would be well advised to discuss it ahead of time with an insurer and even get a surveyor involved from the outset.

Because of the safety issues surrounding the voltages involved in electric propulsion, Fischer Panda has decided to limit its DC product line to boats weighing 10 tons or less. A company representative we spoke to said that while Fischer Panda currently sells DC generators up to 48 volts in the USA for marine use, it “won’t touch” high-voltage DC because it’s lethal.

A proposed collaboration with Catalina Yachts to fit a diesel-electric system in a Catalina-Morgan 440 never came to fruition due to budget constraints, according to Fischer Panda. But in Europe, Fischer Panda teamed up with Whisperprop to equip a Bavaria 49. (Beyond the fact that one of its boats was used, Bavaria Yachts was not involved in the project.) According to Fischer Panda, after evaluating the Bavaria project, the company decided that the diesel-electric AC system is a niche product that wouldn’t interest their prime market: original equipment builders.

“Although the AC system has some advantages in the improved response of the electric motors … and the quietness of the system, the desired fuel efficiency and weight savings were not evident,” Fischer Panda reported.

Fischer Panda considers the DC system to be more suitable for its North American customers. Although it’s limited in output due to its limited battery voltage of 48 volts, it is still able to power multihulls up to 10 tons.

Currently, much of the movement toward electric drives is taking place in the catamaran world. This makes sense when you consider that a single diesel generator can, in theory, provide all the boat’s electrical needs and also take the place of two diesel-propulsion engines. Taking the lead in the field, Lagoon Catamarans introduced in 2006 the Lagoon 420. Originally offered only as a hybrid, it now is also available in two diesel versions. Corsair Marine is building the Corsair 50 catamaran around the Glacier Bay diesel-electric drive, but the boat’s launch date—formerly set for this summer—has been postponed.

Dick Vermeulen, president of Maine Cat, tried the Glacier Bay system in a prototype power cat, but it failed to meet performance expectations, so production models will have conventional diesels. A number of other cat builders have announced hybrid or diesel-electric projects, but feedback on how they perform is scan’t.

So much for the mainstream—but backwater sailors will go their own way, as they always have. As more vendors and components enter the market, the options for do-it-yourselfers or custom-boat customers become broader and more attractive. However, before going ahead with an installation, make sure it’s appropriate to how you plan to use your boat, and even then be prepared to adapt the way you sail to take best advantage of the system’s characteristics. Here’s a rundown of the various types.

Electric Drive Only

Duffy Electric Boats has for years been building electric launches and lake boats that have the simple capability of puttering around in sheltered waters for a period of time determined by battery capacity and speed maintained. A battery charger powered by shore power charges the batteries overnight. Transferring that approach to a sailboat up to about 25 feet used for daysailing and kept near an electrical outlet shouldn’t be too difficult. It won’t offer the assurance of diesel when trying to get home against current or wind, but a proven 36- or 48-volt system will keep you out of uncharted standards territory.

For a bigger boat, more power, a greater range, or a combination of these requirements, it will be necessary to install a large battery bank and almost certainly will entail going to a higher voltage to keep the amps and the cabling needed to carry them manageable. The boat’s range under power will be limited by the weight of batteries, and while lighter lithium-based technology is on the horizon, for now the standard is lead/acid. The fast charging, but expensive pure lead thin plate (PLTP) Odyssey batteries have attracted particular interest among propulsion enthusiasts.

Electric Drive with Regeneration

The next level up in complexity is a “reversible” system. When the boat is sailing, the propeller turns the motor, which then becomes a generator. The electricity it makes is used to recharge the batteries. The capability to regenerate extends the boat’s potential range, but the drag on the propeller slows the boat measurably. One hour of regen will not restore the power consumed by one hour of motoring, but if sailing time sufficiently exceeds motoring time, this arrangement offers considerable range.

A regenerating system does have the potential to overcharge the batteries once they become fully charged and the boat continues to sail fast. The solution is, ironically, to give the motor some “throttle,” which reduces the drag on the propeller and consequently the power output. This phenomenon gives rise to a new technique, that of “electro-sailing” in which sails and an electric motor complement each other. At present, the “throttle” must be adjusted by hand, but developers are working on automatic controls. Field trials of existing regen motors such as the Solomon systems suggest that a small regen motor’s ability to match the output of a much higher-rated diesel have been overstated.

Hybrid Electric Drive

A hybrid system adds to the mix an onboard generator, which is used primarily to maintain charge in the batteries, both those for the propulsion motor and for the house services. This arrangement extends the boat’s capability to lie for long periods at anchor, independent of shore power for electricity and without the need to go sailing for the sole purpose of charging the batteries. A hybrid can motor constantly, as long as there is fuel, but it cannot sustain full speed for long periods. This is because the generator is usually rated at a far lower horsepower than that required to drive the boat at full speed.

Diesel-Electric Drive

In a pure diesel-electric, the electric propulsion motor runs only when the generator is running. Storage batteries are not needed for propulsion purposes, and the generator is the source for all onboard electrical power needs. The rationale behind diesel electric lies in the relationship between a diesel engine’s rate of fuel consumption and the load it’s working under. It burns fuel more efficiently when heavily loaded than when lightly loaded. When the diesel engine is disconnected from the propeller, it can be controlled so that it is working in the upper range of its efficiency regardless of how fast the propeller is turning. Nigel Calder’s series of articles in Professional Boatbuilder magazine (www.boatbuilder.com) beginning with the June/July issue delves deeply into the efficiency discussion surrounding these engines. Systems on large vessels are built around multiple generators that switch on or off according to the power demands of the moment. Translating those efficiencies into a smaller boat scenario has proven to be challenging.

Hype vs. Experience

Maine Cat’s Vermeulen, on the company’s website, describes the sea trials he performed in the Maine Cat 45, a power catamaran. He began with a Glacier Bay diesel-electric system with two 25-kW generators, each weighing about 550 pounds.

“With both generators putting out their full power of 25 kW each … our top speed was a disappointing 8.4 knots, and the assumption that electric horsepower was somehow more powerful than conventionally produced horsepower was in serious doubt.”

He replaced the propellers with a pair with less pitch, which allowed the electric motors to reach their full rating of 1,100 rpm, but that only increased the speed to 9.1 knots.

“These are about the same speeds and fuel burns we get on our Maine Cat 41 sailing cat … powered by twin 29-horsepower 3YM30 Yanmar diesels with saildrives and two-bladed, folding propellers.” At the time he installed them, the 25-kW generators were the highest power available from Glacier Bay.

Vermeulen replaced the diesel-electric system with twin 160-horsepower Volvo diesels. At 9.1 knots, they together burned 2.2 gallons per hour, considerably less than the 3 gallons per hour that the Glacier Bay system burned at the same speed. With the twin Volvos maxed out at 3,900 rpm, the boat made 24.5 knots.

Also among the unconvinced is Chris White, well-known designer of ocean-going catamarans. “To date, I’ve not seen any system that makes sense for a cruising boat,” he says, but he might change his mind, “if someone can show me by building one that delivers an advantage in performance, weight, or cost.”

White sees the current bubble of interest in diesel-electric drives as a fad. In the end, he says, you’re getting the horsepower the diesel creates at the crankshaft, which is basically the same whether it’s delivered to the prop via a conventional reduction gearbox or via a generator and an electric motor. Besides, he says, diesel engines and diesel fuel are understood and available anywhere in the world you might take a sailboat. Complex, electronically controlled electric motors are not.

White’s reservations notwithstanding, it’s in the world of catamarans that we’re seeing most of the applications. At first sight, it does seem logical that replacing three diesel engines—two propulsion and one generator—on a fully equipped cruising cat would result in fuel savings. Still, if the generator is big enough to drive the boat at cruising speed (which in a cat is expected to be in the vicinity of 10 knots) and run the air conditioning at the same time, it will be overkill for the times it’s only needed to operate the boat’s services. For this reason, commercial and military diesel-electric systems employ multiple generators that can be switched on and off according to the power demand of the moment.

Corsair Marine hopes that by installing a diesel-electric system in its 50-foot catamaran, it will be able to descend the weight spiral. Where a conventional installation would involve two 75-horsepower saildrives plus a 6-kW genset, it’s fitting a pair of 28-horsepower electric motors, one 25-kW generator, and a 40-amp, 230-volt battery bank. It expects to save about 700 pounds in equipment weight, some of it through the use of high-voltage, low-current systems, which will in turn reduce the rig requirement, thus the structural weight, and so on toward an estimated overall weight savings in the thousands of pounds.

Corsair’s David Renouf estimates that the boat will cruise at 8 knots and be capable of short bursts at 10. He admits that, until the first boat is launched, his information is “based on extrapolation, not proven numbers.” He says that some clients will add a second 25-kW genset to assure longer periods at 10 knots. Currently, the project is running behind schedule, with a launch scheduled before the end of the year.

Cost and Other Benefits

At the present time, there appears to be no reason to install any proprietary electric drive of any description in the expectation of bettering the economics of a standard diesel drive. The motors and their electronic controllers are sophisticated and expensive. A battery bank sufficient to provide a useful motoring range is a big investment in weight, space, and money. When you add a generator and its peripherals, the cost and weight take another upward leap.

Only the simplest system will begin to pay itself off in terms of fuel not burnt, and then only if the boat sees a great deal of use. A diesel-electric system designed to closely dovetail with the way you use the boat may prove to be more efficient over time than a conventional diesel installation, but until enough systems have been installed and used and data from that use compiled and compared, we can’t know that.

So why even consider going electric? Cleanliness and silence of operation are two qualities that make electric propulsion an attractive proposition for a sailboat, but in order to enjoy them, we have to accept the limitations they impose.

A hybrid or a diesel-electric system enables us to have a single fossil-fuel power source for both propulsion and onboard appliances, but whatever fuel we might save as a consequence of motoring more efficiently for a couple of hours will be inconsequential if we run the generator all night to power the air conditioning.

Conclusions

As we go to press, pickings are slim for sailors looking for an electric solution to the diesel problem. Suppliers of components are few, prices are high, and the feedback on long-term reliability is nonexistent. On top of all this is the elephant in the room: the unexplored safety ramifications that accompany high-voltage DC.

However, none of this should deter the dedicated tinkerer who has funds to match his curiosity and who can live within the parameters imposed by electric propulsion.

Practical Sailor encourages our readers to explore the technology, because ultimately, it is the experimenters who bring us the equipment we eventually come to take for granted.

• Pricing Electric Power for a 30-foot Sailboat
• Special Report
• Electric Engines
• Success in the Real World is a Matter of Perspective

RELATED ARTICLES MORE FROM AUTHOR

I have gotten excited about repowering my Freedom 30 with an electric motor. A fellow Freedom 30 owner completed his refit about 8 months ago and is very happy with the result, although he wishes he had gone with larger Lipo batteries. He chose a motor from electricyacht.com which sells a 10KW package (quietTorque 10) including motor, performance display, throttle and shaft coupler for $6K. Batteries and charger are extra. The motor does does feature a regen capability. Figure a $10K investment. Big bucks for sure but equivalent to a yard installed diesel repower. I would do the install myself.

I am not a cruiser but have done some lengthy passages from San Francisco to Hawaii. Ideal conditions for regen. I expec between regen and a hundred watts of solar, I could have kept the bank topped up the whole way down despite AP loads, etc. The way back? Not so much. Realistically you would need a small generator and a good stock of gas if you wanted to do much motoring, Having said that, one of the boats that sailed down there with me came home with an outboard as his aux power. I think he had ten gallons of gas.

But I am not planning ocean passages in future, I will be sailing the SF Bay and coastal cruising. When I think about eliminating the engine noise, engine maintenance, fuel tank and tank maintenance, diesel hoses, diesel smell, diesel soot, diesel leaks, r=two boxes of hoses and spares. oil changes, coolant changes, transport and disposal of all the waste to the local recycling facility, lugging fuel jugs down to the boat, storing fuel, filling fuel, buying fuel, worrying about spilling fuel. I mean it just goes on and on.

Frankly, I can’t wait. In terms of range, well, I plan to get a hefty battery bank but I also intend to become a better sailor. I’ll slow down and do more sailing. Gee wiz, what a concept. I’ll be more mindful of time and tide, I’ll take advantage of favorable currents and I’ll be ready to anchor and chill when they are not favorable.

Meanwhile, Elon and his competitors are improving battery technology rapidly. Couple of years from now maybe I double range. But, by then, I won’t be worrying about it because I will be a real sailor.

I look forward to reading an update on the state of electric sailboat propulsion 13 years later…

Most of the time we leave the dock, motor for under half a nautical mile to get out of tiny Wilmette harbor and get the sails up, turn off our much abused Yanmar 3GMF, sail around, turn on the engine, lower the sails, and travel another half a nautical mile back to the dock. Almost all at a very low RPM. But, on occasion we motor or motor sail long distances for hours on end, so a battery only system would not work. But how nice it would be if we had electric propulsion for getting in and out of the harbor.

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Resistive forces

Predicting speed, the physics of sailing.

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Bryon D. Anderson; The physics of sailing. Physics Today 1 February 2008; 61 (2): 38–43. https://doi.org/10.1063/1.2883908

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In addition to the recreational pleasure sailing affords, it involves some interesting physics. Sailing starts with the force of the wind on the sails. Analyzing that interaction yields some results not commonly known to non-sailors. It turns out, for example, that downwind is not the fastest direction for sailing. And there are aerodynamic issues. Sails and keels work by providing “lift” from the fluid passing around them. So optimizing keel and wing shapes involves wing theory.

The resistance experienced by a moving sailboat includes the effects of waves, eddies, and turbulence in the water, and of the vortices produced in air by the sails. To reduce resistance effectively by optimizing hulls, keels, and sails, one has to understand its various components.

Moving air has kinetic energy that can, through its interaction with the sails, be used to propel a sailboat. Like airplane wings, sails exploit Bernoulli’s principle. An airplane wing is designed to cause the air moving over its top to move faster than the air moving along its undersurface. That results in lower pressure above the wing than below it. The pressure difference generates the lift provided by the wing.

There is much discussion of whether the pressure difference arises entirely from the Bernoulli effect or partly from the wing’s impact and redirection of the air. Classic wing theory attributes all the lift to the Bernoulli effect and ascribes the difference in wind speeds above and below the wing to the wing’s asymmetric cross-sectional shape, which caused the path on top to be longer. But it’s well known that an up–down symmetrical wing can provide lift simply by moving through the air with an upward tilt, called the angle of attack. Then, despite the wing’s symmetry, the wind still experiences a longer path and thus greater speed over the top of the wing than under its bottom. A NASA website has an excellent discussion of the various contributions to lift by an airplane wing. 1 It disputes the conventional simple version of wing theory and emphasizes that lift is produced by the turning of the fluid flow.

The case is similar for sailboats. A sail is almost always curved and presented to the wind at an angle of attack. The situation is shown schematically in figure 1(a) . The wind moving around the “upper,” or downwind, side of the sail is forced to take the longer path. So the presence of the surrounding moving air makes it move faster than the air passing along the “lower,” or upwind, side of the sail. Measurements confirm that relative to the air pressure far from the sail, the pressure is higher on the upwind side and lower on the downwind side.

Figure 1. Forces on a moving sailboat. (a) Sail and keel produce horizontal “lift” forces due to pressure differences from different wind and water speeds, respectively, on opposite surfaces. (b) The vector sum of lift forces from sail and keel forces determines the boat’s direction of motion (assuming there’s no rudder). When boat speed and course are constant, the net lift force is precisely balanced by the velocity-dependent drag force on the boat as it plows through water and air.

For downwind sailing, with the sail oriented perpendicular to the wind direction, the pressure increase on the upwind side is greater than the pressure decrease on the downwind side. As one turns the boat more and more into the direction from which the wind is coming, those differences reverse, so that with the wind perpendicular to the motion of the boat, the pressure decrease on the downwind side is greater than the pressure increase on the upwind side. For a boat sailing almost directly into the wind, the pressure decrease on the downwind side is much greater than the increase on the upwind side.

Experimenting with what can be done, a beginner finds some surprising results. Sailors know well that the fastest point of sail (the boat’s direction of motion with respect to the wind direction) is not directly downwind. Sailboats move fastest when the boat is moving with the wind coming “abeam” (from the side). That’s easily understood: When a sailboat is moving directly downwind, it can never move faster than the wind because, at the wind speed, the sails would feel no wind. In fact, a boat going downwind can never attain the wind speed because there’s always some resistance to its motion through the water.

But when the boat is moving perpendicular to the wind, the boat’s speed doesn’t decrease the force of the wind on the sails. One sets the sails at about 45° to the direction of motion—and to the wind. The boat’s equilibrium speed is determined by the roughly constant force of the wind in the sails and the resistance against the boat’s motion through the water. If the resistance can be made small, the velocity can be large. That’s seen most dramatically for sail iceboats, which skate on the ice with very little resistance. They can glide along at speeds in excess of 150 km/h with the wind abeam at speeds of only 50 km/h! Of course sailboats plowing through the water experience much more resistance. Nonetheless, some specially constructed sailboats have attained speeds of more than twice the wind speed.

It was recognized centuries ago that a sailboat needs something to help it move in the direction in which it’s pointed rather than just drifting downwind. The answer was the keel. Until the development of modern wing theory, it was thought that one needed a long, deep keel to prevent side-slipping. But now it’s understood that a keel, like a sail, works by providing sideways lift as the water flows around it, as shown in figure 1(a) . A keel must be symmetrical for the sailboat to move to either side of the wind.

A keel works only if the motion of the boat is not exactly in the direction in which it’s pointed. The boat must be moving somewhat sideways. In that “crabbing” motion, the keel moves through the water with an angle of attack. Just as for the sails in the wind, that causes the water on the “high” (more downstream) side of the keel to move faster and create a lower pressure. Again, the net lift force on the keel is due to the combination of that decreased pressure on the high side and increased pressure on the other (low) side.

In figure 1(b) , the keel lift thus generated points almost in the opposite direction from the lift provided by the sails. The two vectors can be resolved into components along and perpendicular to the boat’s direction of motion. For a sailboat moving in equilibrium—that is, at constant speed in a fixed direction—the transverse lift components from sail and keel cancel each other. The component of the driving force from the sails in the direction of motion is the force that is actually moving the boat forward. For equilibrium motion, that force is balanced by the opposing component of the keel lift plus the total resistive force.

Wing theory, developed over the past 100 years for flight, indicates that the most efficient wing is long and narrow. Vortices produced at the wing tip cost energy. A long, narrow wing maximizes the ratio of lift to vortex dissipation, thus providing the best performance for a given wing surface area. That also applies to sailboat sails and keels.

It is now recognized that the most efficient keels are narrow from front to back and deep. Such a keel can have much less surface area than the old long keels. Less area means less resistance. Most modern racing sailboats, such as those used in the America’s Cup races, have deep, narrow keels that are very efficient at providing the lift necessary to prevent side-slipping. Of course, such keels are a problem for recreational sailors in shallow waters.

A sailboat experiences several kinds of resistance. The first is simply the resistance of the hull moving through water. As the boat moves, it shears the water. Water molecules adhere to the hull’s surface. So there must be a shear—that is, a velocity gradient—between the adhering molecular layer at rest with respect to the hull and the bulk of water farther away. The shear means that van der Waals couplings between water molecules are being broken. That costs energy and creates the resistive force, which becomes stronger as the boat’s speed increases. The energy dissipation also increases with the total area of wetted surface.

Although the effect is called frictional resistance, it’s important to realize that the resistive force in water is basically different from the frictional force between solid surfaces rubbed together. To reduce ordinary friction, one can polish or lubricate the sliding surfaces. That makes surface bumps smaller, and it substitutes the shearing of fluid lubricant molecules for shearing of the more tightly bound molecules on the solid surfaces.

For a boat moving through water, however, polishing the hull doesn’t eliminate the shearing of the molecules of water, which is already a fluid. The resistive force cannot be reduced significantly except by reducing the wetted surface. It does help to have a smooth surface, but that’s primarily to reduce turbulence.

The generation of turbulence is a general phenomenon in the flow of fluids. At sufficiently low speeds, fluid flow is laminar. At higher speeds, turbulence begins. Its onset has to do with the shearing of the molecules in the fluid. When the shearing reaches a critical rate, the fluid can no longer respond with a continuous dynamic equilibrium in the flow, and the result is turbulence. Its onset is quantified in terms of the Reynolds number

where ν is the velocity of the flowing fluid, μ is its viscosity, ρ is its density, and L is the relevant length scale of the system. Rearranging factors in equation (1) , one can think of R as the ratio of inertial forces ( ρν ) to viscous forces ( μ /L). In the late 19th century, English engineer Osborne Reynolds found that, with surprising universality, turbulence begins when that dimensionless parameter exceeds about a million.

For a boat of length L moving through water at velocity ν to see when turbulence begins in the flow along the hull, R is about 10 6   Lν (in SI units). A typical speed for a sailboat is 5 knots (2.4 m/s). At that speed, then, one should expect turbulence for any boat longer than half a meter. (Used worldwide as a measure of boat speed, a knot is one nautical mile per hour. A nautical mile is one arcminute of latitude, or 1.85 km.)

Because turbulence dissipates energy, it increases the resistance to motion through the water. With turbulence, a sailboat’s resistance is typically four or five times greater than it is when the flow along the hull is laminar. A rough surface will cause turbulence to be greater and begin sooner. That’s the main reason to have a smooth hull surface.

Turbulence also occurs in the air flowing along the surface of the sail. Water is a thousand times denser than air and 50 times more viscous. So for the air–sail system one gets

For a typical wind speed of 5 m/s, then, one gets turbulence if the sail is wider than about 3 meters. When turbulence forms in the air flow along the sail, the desired pressure difference between the two sides of the sail—its lift—is diminished.

Another important resistive force comes from vortex generation at the bottom of the keel and at the top of the sails. When the air or water moves around the longer-path side of the sail or keel, its speed increases and therefore its pressure falls. As the air or water moves along the sail or keel, it will respond to the resulting pressure difference by trying to migrate from the high-pressure side to the low-pressure side. Figure 2 sketches that effect for a keel. What actually happens, as shown in the figure’s side view, is that the flow angles a bit up on one side and down on the other. When those flows meet at the back of the sail or keel, the difference in their arrival angles has a twisting effect on the fluid flow that can cause a vortex to come off the top of the sail or the bottom of the keel.

Figure 2. Vortex formation by the keel. Unless the boat is sailing straight ahead, there’s a pressure difference between the two sides of the keel. As a result, the water flow angles down on the high-pressure (lower water-speed) side and up on the low-pressure side, creating a twist in the flow that generates vortices behind the bottom rear of the keel.

The effect is well known for airplane wings. Called induced drag, vortex formation costs energy. Figure 3 shows vortices generated at the tops of sails by racing sailboats moving through a fog. A long keel will generate very large vortices. By making the keel short and deep, one can increase the ratio of lift to energy dissipated by vortices. The same is accomplished—especially for sailboats racing upwind—by having tall, narrow sails. It’s also why gliders have long, narrow wings.

Figure 3. Sailtops form vortices visible in fog. The boats were participating in the 2001–02 Volvo Ocean Race off Cape Town, South Africa.

Because it’s often impractical to have a short, deep keel or a narrow, long wing, one can install a vane at the tip to reduce the flow from the high-pressure to the low-pressure side. On planes they’re called winglets, and on keels they’re simply called wings. A modern recreational or cruising sailboat will have a keel that’s a compromise between the old-fashioned long keels and the modern deep, narrow keels—with a wing at the bottom rear end to reduce induced drag. Such keel wings were first used by the victorious sailboat Australia II in the 1983 America’s Cup race. Modern wing theory also suggests that to minimize induced drag, keels and sails should have elliptic or tapered trailing edges. 2 Such shaped edges are now common.

A sailboat also has a resistance component due simply to its deflection of water sideways as it advances. That’s called form resistance, and it obviously depends on hull geometry. It’s easy to see that narrow hulls provide less resistance than do wider hulls. Any boat will always be a compromise between providing low form resistance and providing passenger and cargo space. Seeking to minimize form resistance for a given hull volume, shipbuilders have tried many basic hull shapes over the centuries. Even Isaac Newton weighed in on the question. He concluded that the best hull shape is an ellipsoid of revolution with a truncated cone at the bow.

Extensive computer modeling and tank testing have resulted in a modern hull design that widens slowly back from the bow and then remains fairly wide near the stern. Even with a wide stern, designers try to provide enough taper toward the back to allow smooth flow there. That taper is often accomplished by having the stern rise smoothly from the water rather than by narrowing the beam. If the flow from the stern is not smooth, large eddies will form and contribute to resistance.

As a boat moves through water, it creates a bow wave that moves with the speed of the boat. Water waves are dispersive; long waves propagate faster than short ones. Therefore the length of the full wave generated by the bow is determined by the boat’s speed. As a boat starts to move slowly through the water, one sees at first a number of wave crests and troughs moving down the side of the hull. As the boat speeds up, the wavelength gets longer and one sees fewer waves down the side. Eventually at some speed, the wave will be long enough so that there’s just one wave down the side of the boat, with its crest at the bow, a trough in the middle, and another crest at the stern (see figure 4 ). That’s called the hull speed.

Figure 4. Moving at hull speed, a sailboat generates a bow wave whose wavelength just equals the length of the boat’s water line. The wave crests at bow and stern, with a single well-formed trough in between.

If the boat speed increases further, the wavelength increases so that the second crest moves back behind the boat and the stern begins to descend into the trough. At that point, the boat is literally sailing uphill and the resistance increases dramatically. That’s called wave resistance. Of course, if one has a powerboat with a large engine and a flat-bottomed hull, one can “gun” the engine and cause the boat to jump up on the bow wave and start to plane on the water’s surface. Most sailboats don’t have either the power or the hull geometry to plane. So they’re ultimately limited by wave resistance.

The wave-resistance limit also applies to all other so-called displacement boats: freighters, tankers, tugs, and most naval vessels bigger than PT boats—that is, any boat that can’t rise to plane on the surface. The functional dependence of water-wave speed ν on wavelength λ is well known. From the limiting case for deep-water waves for the solution of the two-dimensional Laplace wave equation, 3 or from a simple derivation due originally to Lord Rayleigh, 4 one gets ν = g λ / 2 π ⁠ , where g is the acceleration of gravity. In the form commonly used by sailors in the US,

where the λ is in feet and ν is in knots.

If one equates the wavelength to the waterline length of a boat, equation (3) gives the boat’s hull speed. For a sailboat with a waterline length of 20 feet (6 m), the hull speed is 6 knots. For a large cruising sailboat with a waterline of 40 feet (12 m), it’s about 8 knots. And for a 300-foot-long naval vessel, it’s 23 knots. In practice, it’s very difficult to make a displacement boat go faster than about 1.5 times its hull speed.

Combining all the components of resistance for a sailboat moving at close to its hull speed, one finds that the frictional resistance contributes about a third of the total, and the wave resistance another third. Form resistance accounts for about 10%, as does the induced drag from vortex generation at the bottom of the keel. The assorted remaining contributions, including eddy formation behind the boat and aerial vortex generation by the sails, provide the remaining 10 to 15%. Of course the fractional contributions vary with boat speed, wave conditions, and the direction of motion relative to the wind.

One can exploit the physics of sailing to calculate boat speeds for a given sailboat for different wind speeds and points of sail. Such calculations are usually performed iteratively by computer programs that start from two basic vector equations to be solved simultaneously:

Here F drive is the total driving force in the direction of motion provided by the wind in the sails, and F resistance is the sum of all the resistive forces. The torques M heel and M righting are the heeling and righting moments caused by the wind in the sails and the weight of the hull and keel.

The force of the wind on the sail is calculated as a lifting force perpendicular to the apparent wind direction and a drag force in the direction of the apparent wind. (The apparent wind is the wind as perceived by an observer aboard the moving vessel.) These lift and drag forces are then resolved into components along and perpendicular to the direction of motion. The net force in the direction of motion is then F drive ⁠ , and the net force perpendicular to the boat’s motion is what produces the heeling moment. The two equations in ( (4) ) must be solved simultaneously because the angle of heel affects the total driving force.

Following Bernoulli’s principle, one takes the force of the wind in the sails to be proportional to the total sail area times the square of the apparent wind speed. The actual forces are then obtained with empirical lift and drag coefficients, given as functions of sail geometry and angle of attack. Frictional resistance is proportional to the hull’s wetted surface area and increases as the square of the boat’s speed. All the various contributions to total resistance involve empirical coefficients. Wave and form resistance are expressed as functions of the hull’s “prismatic coefficient,” which is an inverse measure of the tapered slimness of its ends.

There are simple and complex speed-prediction computer programs. Some that have been refined over decades for racing applications are kept private and closely guarded. Figure 5 shows the results of calculations I performed for a 30-foot (10-m) cruising sailboat using a publicly available program. 5 The figure shows the calculated boat speed as a function of wind speed and point of sail. The predicted boat speeds are greatest when one is sailing about 90° away from the wind direction. Sailors call that beam reaching. It yields a boat speed of about half the wind speed.

Figure 5. Speeds predicted by a computer model 5 for a 10-meter-long cruising sailboat, plotted for three different wind speeds from 6 to 20 knots as a function of the angle of the boat’s motion relative to the wind direction. (10 knots = 18.5 km/h.) An angle of 180° means the boat is “running” with the wind directly at its back. The fastest speeds are predicted when the boat is “beam reaching,” that is, moving at about 90° to the wind. The boat even makes some progress when it’s “close hauling” almost directly into the wind.

Such calculations are confirmed experimentally, with a degree of accuracy that depends on the sophistication of the model and on how much the program has been tuned for a specific kind of sailboat. Broadly speaking, a sailboat is faster if it is longer and narrower, with bigger sails and a smaller wetted surface. Such general rules can, of course, yield a boat that’s longer than one wants, or tips over too easily, or has too little room inside.

So every design feature is a compromise between competing needs. For sailing downwind, one wants fairly square sails, which are best at catching the wind. But for sailing upwind, taller, narrower sails are best, because they maximize the ratio of lift to energy lost by generating vortices. The most efficient keel is deep and narrow, to maximize lift with minimal surface area. But a deep keel is problematic in shallow waters. Shorter keels with wings or bulbs at the bottom usually represent the best compromise for overall sailing.

What’s the highest speed a sailboat can reach? The trick is to reduce resistance. An iceboat can outrun the wind because it has so little resistance. For a sailboat, the resistance comes primarily from having to plow through the water. The best way to reduce that resistance is to move less and less of the boat through the water. One answer is hydrofoils. They are vanes placed below the hull that raise it out of the water as the boat speeds up.

Sailboats with hydrofoils have reached speeds of more than 40 knots when the wind speed was barely half that. One such craft is shown in figure 6 . These vessels are not usually practical for cruising and other normal recreational activities. They’re sometimes dismissed as low-flying aircraft. A more practical alternative is the catamaran—a double-hulled sailboat. Catamarans are being developed to provide relatively stable, fast sailing. Although they are more expensive than traditional single-hull sailboats for a given amount of living space, catamarans are becoming increasingly popular.

Figure 6. A hydrofoil sailboat with solid, winglike sails, moving at about twice the wind speed with the wind abeam—that is, blowing from the side.

Bryon Anderson is an experimental nuclear physicist and chairman of the physics department at Kent State University in Kent, Ohio. He is also an avocational sailor who lectures and writes about the intersection between physics and sailing.

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The Most Popular Types Of Sails On A Sailboat

A sloop-rigged sailboat typically features a mainsail, a headsail, and an additional light-wind sail, such as a spinnaker or Gennaker. The mainsail is rigged aft of the mast, while the headsail is attached to the forestay. The two most commonly used headsails are the Genoa and Jib.

The sails are vital parts of a sailboat since you obviously couldn’t sail without them! There are many different sails depending on the type of sailboat and its rig configuration, and we’ll walk through them together in this article.

The different types of sails on a sailboat

We can divide the selection of sails on a sailboat into three categories:

• Standard sails

Light-wind sails

• Storm sails

Each category serves different purposes depending on the vessel’s rig configuration and the sail’s functionality. 

The standard sails

The standard sails usually form a sailboat’s basic sail plan and include :

• The Mainsail
• The Staysail
• The Mizzen sail

These sails are the ones that are used most frequently on sloop, ketch, and cutter-rigged sailboats and are usually set up to be ready to use quickly.

Headsails are often rolled up on a furler, while the main and mizzen sail are stored on the boom or furled into the mast. 

The halyards and sheets are kept within easy reach, making these sails the primary choice in most situations. Let’s dive further into each of them.

The mainsail is a triangular sail that flies behind the mast on top of the boom . Although it may not always be the largest sail on the vessel, we commonly refer to it as “the main.”

It is a vital sail, and keeping the sail shape trimmed properly on every point of sail is crucial for the stability and performance of the boat.

A Jib sail is a headsail that does not overlap the mainsail. It is typically between 100% and 115% of the foretriangle but can also be smaller. The foretriangle is the triangular area formed by the mast, deck, and forestay. The Jib is often used with a self-tacking system involving a sheet traveler in front of the mast.

This sail is often seen on newer boats with fractional rigs, which typically have a larger mainsail area than the headsail area. However, the Jib is versatile and also used in other configurations.

People often mix the terms Genoa and Jib. Many refer to any headsail as a Jib, which is incorrect. I personally prefer to use the correct terms to avoid confusion .

A Genoa sail resembles a large Jib but extends past the mast and overlaps the mainsail. Genoas are usually larger than 115% of the foretriangle , with sizes ranging from 120% to 150%. They are often used on vessels with masthead rigs and smaller mainsails but are also common on fractional rigs.

The Staysail is typically found on cutter rigs and is set on the inner forestay or cutter stay. It can be combined with other sails, such as a Jib, Genoa, or Yankee, or on its own in stronger winds.

The Staysail is also useful when sailing downwind, as it can be paired with a headsail and extended to opposite sides of the boat using a pole.

The Yankee sail resembles a Genoa and Jib but has a high-cut clew. This shape allows for improved airflow when used with another headsail. The Yankee is often used on cutter-rigged boats in combination with a staysail and is known for its versatility in different wind conditions. 

Mizzen Sail

A mizzen sail is similar to the mainsail, only smaller . It is set on the aft mast of a boat with multiple masts, such as a ketch rig. The mizzen sail is usually used to provide balance and stability to the vessel and provides additional power when sailing downwind.

Another handy usage is to fly the mizzen at anchor to keep the bow up against waves and swell.

The light-wind sails are large, made of thin nylon, and typically shaped like a half-balloon. They are a type of headsails that are great when the winds are too light to fill the standard headsail and are often used when sailing downwind.

The four most commonly used light-wind sails are:

• The Spinnaker
• The Gennaker
• The Code Zero
• The Parasailor

They all provide excellent forward propulsion on a sailboat but usually require some extra rigging to be set. 

Experienced cruisers love to use light-wind sails in nice weather, but they have a critical weakness to be aware of. These sails easily get overpowered when the wind increases, and I strongly advise being careful and observant of the wind conditions when flying them.

(Yes, I have managed to rip mine on one occasion due to getting overpowered, but that’s a different story…)

Let’s continue and take a closer look at each of the light wind sails.

A Spinnaker sail is a large, lightweight downwind sail used at deep angles between 120 and 180 degrees. It is symmetrical in shape with two clews and is often brightly colored. 

The Spinnaker is set by using a pole to extend the sail’s clew to the vessel’s side. Then, a sheet is attached to the other clew and led back to the stern of the boat. 

A Gennaker sail combines the characteristics of the Genoa and Spinnaker. It is made of nylon like the Spinnaker but is asymmetrical like a Genoa and rigged slightly differently. The tack is attached to the bow, and the clew has a sheet led aft to the cockpit. The Gennaker can be equipped with a snuffer to make it even easier to set up and take down.

It is popular among cruisers because it is simpler to use than a spinnaker and it doesn’t require a pole. The sail is effective at angles between 90 degrees and almost all the way down to 180 degrees, making it versatile for various light-wind conditions.

A Parasailor is similar to the Spinnaker in many aspects but has some distinct differences. It has a double-layer wing that inflates as the sail is filled with air, creating a batten-like effect pushing the leech out while providing lift to the bow. 

The wing also helps to prevent the rolling movements you get with a Spinnaker and the collapsing of the leech that can occur with a Gennaker at deep angles.

This makes the parasailor effective at sailing angles between 70 and 180 degrees dead downwind. Parasailors can be set like a Gennaker when reaching or with a pole like the Spinnaker for running downwind.

A Code Zero sail combines some elements of the Genoa and Gennaker. Unlike the Gennaker, the Code Zero has a different shape, allowing it to be used while sailing upwind.

Another benefit is that it can be used with a furler which makes it easy to roll in and out. However, it can’t replace the Gennaker or Spinnaker entirely, as it is not effective at sailing angles deeper than 120 degrees.

If you see a big yacht with three forestay’s, the forward one probably holds a code zero sail. A bow spirit allows the ability to fly additional light wind sails as well!

Storm Sails

The storm sails consist of a small Mainsail and Jib in heavy-duty materials designed for rough conditions. These sails enable us to maintain speed and stability in the boat in severe weather too strong for the standard sails.

Storm sails are often brightly colored , such as red, orange, or yellow, to make them more visible at sea.

Storm Mainsail

A storm mainsail is used when the reefing setup doesn’t allow the standard mainsail area to be reduced enough to prevent overpowering. The sail can handle rough conditions and is excellent for maintaining stability.

A storm Jib is used when the headsail has been furled to the point where it is no longer effective. It is especially useful for sailboats rigged with a Genoa, as the Genoa gets inefficient when heavily reefed. As the storm Jib is smaller than the standard headsail, it also lowers the center of gravity, making the vessel heel less and become more stable.

Explaining the terms for the parts of a sail

Let us talk some more about sails. The goal is to go sailing, right?

Identifying the different parts of the sails is crucial to understanding which lines go where.

Let’s zoom in on a sail and break down the terms :

The head is the top corner of the sail . Most mainsails have a headboard or plate where the halyard is connected, while headsails use a metal ring. A halyard is a line we use to raise and lower sails with.

The leech is the aft part of a sail , located between the clew and head. We use a combination of the outhaul, main sheet, and traveler to trim and adjust the leech on the mainsail.

The headsail’s leech is trimmed by adjusting sheet tension and angle according to the wind speed and direction. A traveler is a track with a movable car or pulley system for adjusting the position and angle of a sheet, and most sailboats have one main traveler for the mainsail and car tracks along the side decks for the headsail. 

The luff of a sail is the front part of the sail between the tack and head. On a mainsail, the luff runs vertically along the mast and along or close to the forestay on a headsail. Headsails are often equipped with luff foam to help maintain their shape when partially reefed on a furler.

Battens are slats or tubes inserted into pockets on the mainsail to help the sail maintain its shape and increase its lifespan . A traditional sail hoisted and lowered on the boom typically has horizontal battens. Vessels with in-mast furling can use vertical battens instead of horizontal ones. 

• A fully battened Mainsail has the battens run through the entire sail length from the luff to the leech.
• A standard battened main sail has the battens along the sail’s leech.

Telltales are small ropes, bands, or flags attached to a sail to give an indication of the airflow around the sail. They help us understand how the wind affects the sail and allow us to fine-tune the trim for optimal performance. Telltales are usually found on the mainsail’s leech and in the front of the headsail’s leech.

The clew of a sail is the lower aft corner and where the outhaul is connected on a mainsail. Headsails have sheets attached to their clew for controlling and trimming the shape and tension.

The tack is the lower, forward corner of a sail.  On a traditional Mainsail, the tack is attached to the Gooseneck, a hinge in front of the boom attached to the mast.

With in-mast furling, the tack is connected to the furling mechanism. This mechanism is used to roll the sail into the mast.

The headsails tack is connected to a furler drum on the forestay on most sailboats. Vessels using traditional hank-on headsails connect the tack to a fixed point on the bow.

The foot of the mainsail is the bottom portion of the sail between the clew and the tack. It is trimmed using the outhaul, a line attached to the clew, and used to adjust the tension on the foot of the sail. Some mainsail are configured loose-footed, and others are attach-footed.

The foot of the headsail is trimmed by adjusting the tension and angle of the sheets, which are the lines used to control the headsail’s clew. We use cars, or pulleys, to adjust the angle of the sheets and thus the trim of the headsail.

Traditional and less commonly seen sails

We’ve now looked at the most commonly used sails and walked through the different parts of them. But what about the less common ones? The art of sailing has a rich history, with some unique sail designs that we rarely see today.

Read on if you want to peek into some traditional sails, or skip straight to popular sail and mast configurations here.

Square sails

Square sails are rectangular and usually set across a ship’s mast, mostly seen on traditional square-rigged sailing ships and Viking ships. These sails are efficient for downwind sailing and are hung from horizontal spars called yards. Though not as agile as modern fore-and-aft sails when sailing upwind, they were central to naval exploration for centuries. Today, they’re mainly seen on traditional vessels and tall ships, symbolizing maritime heritage.

If you’ve been to Martinique in the summer, you may also have noticed the round skiff sailboats the local fishermen traditionally used for fishing in the Atlantic Ocean with their distinctive big squared sails. Tour de Martinique des Yoles Rondes is a popular yearly event where the locals race and show off these beautiful old boats with colorful sails!

A gaff sail is a traditional four-sided sail held up by a horizontal spar called the “gaff.” They are used on classic gaff-rigged sailboats and allow for a larger sail area with a shorter mast. Gaff-rigged boats were traditionally popular and usually carried 25% more sail area than the equivalent Bermudan rig, making them fast on a downwind run. The Gaff rig could also carry a topsail between the gaff and the mast.

However, they don’t sail well to windward, and modern designs have shifted towards triangular sails for better upwind performance.

Jib-headed topsail

The Jib-headed topsail is a small triangular sail used on gaff rigs and is set between the gaff and the top of the mast.

A lug sail is an angled, four-sided sail that attaches at a point on its top side, making it hang tilted. The sail is simple to use and often found on smaller or older boats. There are different types, like standing, dipping, and balance lugs, each hanging differently around the mast.

The lug sail evolved from the square sail to improve how close the vessels could sail into the wind. Because of their upwind performance, fishermen used them widely in Europe from the seventeenth through the nineteenth centuries.

Sprit sails

The spritsail, with its unique four-sided design, stands out thanks to a diagonal support called the “sprit.” It was traditionally popular in Thames sailing barges due to its ability to accommodate high-deck cargo. These days, it’s primarily found in smaller boats like the Optimist dinghy in a variant called “leg of mutton spritsail.”

The spritsail was also used in traditional wooden boats like the fearing version of the Oselvar wooden boat traditionally used in western Norway.

It is also commonly used by the indigenous Guna Yala tribes in Panama in their dugout Ulu’s up to this day. We saw plenty of them when we cruised along the coast, and some of them approached us to sell us their delicious catch of the day!

Lateen sails

A lateen sail is a triangular sail set on a long spar angled on the mast. It was originally popular in the Mediterranean and on Arab shows, and its design enhanced maneuverability and played a crucial role in historic sea exploration.

The lateen sail was used on lateen rigs, the predecessor to the Bermuda rig – one of today’s most commonly used rigs!

Which brings us to the following topic:

Popular sail and mast configurations 

There are many different rigs and sail configurations between sailing vessels. From the old-school square rigs to schooners, gaff rigs, and more. However, this article will focus on the three most popular rigs seen on modern sailboats:

• The Bermuda Sloop Rig
• The Cutter Rig
• The Ketch Rig

The three rigs have similarities and differences between their sail and mast configurations. We’ll walk through each of them to understand how they utilize their different types of sail.

If you want to learn more about other rigs, take a look here .

Bermuda Sloop Rig

The Bermuda sloop rig is the most common rig on modern vessels. It is characterized by a single mast, a triangular mainsail, and a headsail. This rig is named after the Bermuda Islands, where it was developed in the 17th century. 

Some of the key features of the Bermuda sloop rig:

• The mast is typically tall and raked, which allows for a large sail area and excellent stabilit y.
• The mainsail is attached to the mast and boom. It is usually combined with a single headsail at the front of the boat, making it powerful and easy to sail.
• The Sloop is usually equipped with a masthead or fractional rig and flies a Jib or Genoa as its primary headsail.

The Bermuda Sloop rig is known for its simplicity, is often used for racing and cruising, and is popular among sailors worldwide.

The cutter rig is very similar to the sloop rig. The significant difference is that it has a single mast and two headsails – a Staysail and a Yankee. The cutter rig is known for its versatility due to the multiple options in sail plans and the double headsail setup.

Some key aspects that separate the Cutter from the Sloop:

• The rig is often more robust than its Sloop sister because of the additional cutter stay and running backstays.
• The mast is located closer to the center of the boat.
• The Cutter has a staysail on the inner forestay and a Yankee sail on the outer. The sails can be used in combination with each other or independently.
• Tacking the headsail between the forestay and cutter stay is more involved than on a sloop.
• The Cutter rig has two similar variations: the Slutter rig and the Solent rig.

Like the Sloop, the Cutter rig is relatively easy to operate. Still, the additional headsail and rigging make it costlier to maintain. It is also less suitable for racing than the Sloop, but the added versatility helps in different weather conditions and makes it an excellent choice for cruisers.

The ketch rig is also similar to the Sloop but has an additional mizzen mast placed further aft of the main mast. Another mast gives it the advantage of even higher versatility in sail plans. The ketch typically uses three sails. The mizzen sail, a mainsail, and a headsail. The mizzen mast also allows it to fly a second light-wind sail. 

Here are a few more distinctions of the ketch rig:

• The ketch typically carries a smaller mainsail than a similarly sized sloop and a smaller mizzen sail.
• A small mizzen and a medium mainsail are easier to handle than one large mainsail.
• The additional mizzen sail makes the vessel easy to balance and gives extra stability downwind.
• The ketch usually doesn’t point as close to the wind as the Sloop and Cutter.

The headsail setup on a ketch is generally the same as for the Sloop. But the ketch can also be rigged as a cutter ketch, which gives it the benefits of the cutter rig! The tradeoff with a cutter-rigged ketch is the higher complexity and additional rigging, hardware, and sails required.

Final words

Well done, you now have a good grasp of the most common sails and their strengths. We have discussed a few rigs and how they utilize different kinds of sails in various sail plans. Remember that more sail types, other rigs, and even more variations are available. It is a complex topic, but this guide covers the basics and gives you a great starting point.

If you still have questions, look below at the FAQ, or leave me a comment. I’m more than happy to help you out!

A sailboat is only as good as its sails, and sails need wind to work. The next logical step is learning how the wind works when we sail and practicing some wind awareness! Head to the following guide to continue your research: Learn The Difference Between True And Apparent Wind Speed.

FAQ: The Different Types of Sails On A Sailboat

What is the foretriangle on a sailboat.

The foretriangle on a sailboat refers to the triangular area formed between the mast, forestay, and deck. If you want to order a new headsail, for example, you’ll have to measure and supply the sailmaker with these details.

What is the difference between a loose-footed and attached-footed mainsail?

A loose-footed mainsail is attached to the boom only at its corners, leaving the rest of the sail’s bottom edge free. An attached-footed mainsail, on the other hand, is secured to the boom along its entire length. The main difference lies in how the bottom of the sail connects to the boom, with the loose-footed design offering more adjustability in the sail shape.

What is a high-cut clew on a sail?

A high-cut clew refers to the design of a foresail, such as a jib or genoa, where the back lower corner (the clew) is raised or “cut” higher above the deck compared to standard designs. This design allows for better visibility beneath the sail and makes it easier to sail over waves without the sail touching the water, which is especially beneficial for offshore or blue-water cruising. Very high-cut clews are commonly seen on yankee sails on cutter-rigged sailboats.

What is luff foam on a sail?

Luff foam is a padded strip sewn into the forward edge of roller furling sails. It ensures the sail is appropriately shaped when partially rolled up, especially in strong winds. This foam not only helps with sail performance but also protects the sail when it’s furled.

What are the most common sails?

The sloop rig sailboat is the most common and usually features a mainsail, a headsail, and an additional light-wind sail, such as a spinnaker or Gennaker.

What are the different types of sails?

There are several different types of sails, and we can divide the most common into three categories:

The standard sails:

• Mizzen sail

The light-wind sails

The storm sails:

• Storm mainsail
• Storm jib 

What is a spinnaker sail?

A Spinnaker sail is a large, lightweight downwind sail used at deep angles between 120 and 180 degrees.

What is a Jib sail?

A Jib sail is a headsail that does not overlap the mainsail and is set on the forestay. The Jib can also be set up with a self-tacking system, making it very effective when sailing into the wind.

Is Genoa sail the same as a jib?

People often mix the terms Genoa and Jib. The Genoa is different from a Jib sail as it is larger and overlaps the mainsail, whereas the Jib is smaller and does not overlap the mainsail.

What is a Genoa sail?

A Genoa is a headsail larger than the Jib extending past the mast and overlapping the mainsail. The advantage over the Jib is the larger sail area, making it more effective when sailing off the wind.

How many types of sail plans are there?

Sail plans refer to the configuration and arrangement of sails on a boat or ship. While there are countless customizations and variations, the three most common sail plans are:

Sloop: Characterized by a single mast, a triangular mainsail, and a headsail.

Cutter:  Similar to a sloop but has a single mast and carries two or more headsails.

Ketch: Features two masts, with the aft mast (called the mizzen) shorter than the main mast.

What is a Mainsail?

The mainsail is a triangular sail that flies behind the mast on top of the boom.

What is a Gennaker?

A gennaker is basically an asymmetrical spinnaker. A hybrid sail that combines the characteristics of a Genoa and a Spinnaker, designed for sailing off the wind and often used in light to moderate wind conditions.

What is a Storm Jib?

A storm jib is a small, heavy-duty sail used in strong winds or stormy conditions. It is commonly used when the headsail has been furled to the point where it is no longer effective.

What factors determine the type of sail to be used?

The type of sail to be used depends on various factors such as wind conditions, points of sail, sailboat size , and sailing experience. It’s smart to choose the appropriate sail for optimal performance. A Jib, for example, will be more effective than a Genoa while sailing to windward, and vice versa.

How do sails affect the performance of a sailboat?

Sails are the engine of a sailboat. Their design, size, and trim influence the boat’s speed, direction, and stability. Properly adjusted sails capture wind efficiently, allowing the boat to move faster and in the desired direction.

The balance and condition of the sails also impact comfort and safety, with well-maintained sails ensuring optimal performance. The sails are essential in determining how a sailboat performs in various wind conditions.

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Skipper, Electrician and ROV Pilot

Robin is the founder and owner of Sailing Ellidah and has been living on his sailboat since 2019. He is currently on a journey to sail around the world and is passionate about writing his story and helpful content to inspire others who share his interest in sailing.

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• Catalogue 2023
• Exhibitor portal

How much more onboard energy can boats get from wind power?

With the world firmly in transition mode, the move away from non-renewable energy sources is well underway, and nothing is going to stop that now.

Energy from wind has become a feature of our daily lives, it's hard to go anywhere these days without seeing wind generators on land or offshore. This is particularly true for those of us living in the Netherlands, where the wind tends to blow across the lowlands fairly reliably for most of the year, and wind turbines have become part of the landscape. So, it's not for nothing, that sailing is such a hugely popular hobby in Holland.

Future of wind power

But what about the future of wind power, and its place in the mix of renewable energy sources that are available for providing sustainable onboard power for all types of boats in the marine industry.

Several thoughts around this subject have occurred to me just recently, and these were triggered partly by Ken Wittamore's comments on the METSTRADE sustainability panel last December. Ken mentioned that energy harvesting from a range of renewable sources is becoming the norm in order to meet the demand for more (sustainable) power onboard these days, and that improved performance from wind generators was playing its part, along with ever larger solar arrays.

Eco-friendly ‘Soliloquy’: combining wind energy, solar and hybrid technologies

These ideas prompted me to cast my mind back to 2009, when I was at a Superyacht conference in Palma de Mallorca. A young man named Alastair Callender was there, creating a lot of interest with a scale model of his eco-friendly yacht design named 'Soliloquy.'

I remember chatting to Alastair, and being impressed with the fact that he had just left university, and combining his passion for yachting with a concern for the environment, he had designed the 58 metre eco-friendly superyacht as part of his final year study work.

Apparently inspired by Masdar City, a zero emission, self sustainable, ultra-green project in the Middle East, the young student had managed to put together an award winning innovative design which certainly got the whole marine industry thinking. Looking back now, Soliloquy was a futuristic view on ‘things to come’, when you consider that Alastair’s actual work input was carried out well over a decade ago.

Clearly the design of the yacht was very much focused on the potential to capture wind power as part of the energy mix. Aimed at combining wind power, solar power and hybrid motor technologies, she had three large rigid wing sails, fitted with solar panels that could move independently in order to make optimal use of wind and / or sun. These were able to be folded down, giving the yacht a sleek elegant profile when they were not in use.

Energy Observer vessel added ‘Ocean Wings’ for wind energy

A couple of years ago, I had the privilege to visit the Energy Observer vessel during her stopover in Amsterdam. As most people know by now, she is a floating laboratory cruising the oceans of the world, whilst perfecting renewable energy solutions such as hydrogen for future maritime use. Whilst in Amsterdam she was being fitted with a set of ‘Ocean Wings’ which the crew described as wind turbine thrusters.

The purpose of this addition to the vessel’s arsenal of renewable energy sources, was to reduce power consumption, accelerate speed, and most crucially, to enable the production of energy and hydrogen whilst navigating. The pair of wings each have a surface area of 31.5 m², and are self-supporting with a rotation capacity of 360°.

The installation of the wings was encouraged by a number of previous wind power simulation exercises carried out on a variety of different types of boat. The data produced from such tests gave promising results on energy savings of between 18% and 42%.

Wind power has significant potential for the maritime industry. Taking into account the fact, that 90% of global commerce is transported at sea, and emits into the atmosphere large amounts of C02, plus fine particle toxic pollutants such as nitrogen dioxide (NOx), and sulfur dioxide (SOx.)

Windship Technology promises a breakthrough

Bringing the story right up to date, and following the same promising use of wind as a naturally occurring element, the UK based Windship organisation have recently announced successful trial results in their development of a patented triple wing rig.

Following extensive computational performance testing by the Wolfson Unit at Southampton University in UK, the Windship rig design has been confirmed to achieve significant fuel and emission savings, conservatively estimated at 30% on a typical 125,000 ton (deadweight) commercial cargo ship.

Windship have patented their technology which includes multiple pairs of leading and trailing aerofoil sections, supported on a rotatable spar, with an adjustable angular position. And in order to clear the decks for port navigation and cargo handling purposes, the 48m wing rig structure is designed so that it can be lowered and stowed.

When it comes to meeting future emission reduction targets, the company claims to be confident in having the most practical solution for operators of large commercial cargo ships. This is on the basis of the wing rigs being part of a ‘whole ship design,’ where large solar power arrays, carbon capture, optimised hull shapes, and specialised weather routing software are all part of the package.

Doesn’t much of this sound similar to Alasdair Callender’s Soliliquy eco-friendly superyacht design concept from 12 years ago? And although this project has been focused on harnessing wind power for commercial ships, I do wonder how much of it could be applied to leisure yachting?

Wind generators onboard, who would be without one?

Turning our attention back to what we might expect to see at the upcoming METSTRADE, how about the extensive choice of reliable, powerful and technically advanced wind generators that visitors will be able to peruse at the show.

There is no question that the humble wind generator has come a long way since the early versions came to the market several decades ago. Back then, wind generators were enthusiastically installed on many sailing yachts by owners who were looking for a little more power independence when at sea. After all, if you are relying on wind to propel your sailing boat, why not take advantage of the same free breeze to provide some onboard power.

Many of the early models of onboard wind generators were bulky, noisy, unreliable, poorly marinised, and not very aesthetically pleasing to the eye, but that has all changed now.

These days they come in all shapes and sizes, built around solid state electronics, encapsulated in all weather enclosures, and to suit a wide range of budgets and demands. The benefits of computer aided design, and composite construction have produced some elegant streamlined looking wind generators, some with inbuilt features such as self feathering blades, automatic braking, overcharge protection etc. And thankfully, quiet operation that doesn’t keep everyone on the anchorage awake all night.

See you at METSTRADE 2021…  Let's get together and ‘shoot the breeze’ in Amsterdam! 

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Energy on your Boat

Details and tips for understanding energy on your boat.

Managing Energy on your boat is like managing water on your boat – there is a limited supply and you have to constantly top it up as you use it.

With the maturity of Lithium-Ion batteries and high capacity storage, people look for smarter and faster ways to generate more energy on your boat. While solar will always be a cheap and easily available source of energy, for today’s modern boat with all the desired creature comforts – such as the array of electronics, refrigeration, electric ovens, water heaters, water makers, air conditioning, and more – solar cannot keep up.

Power vs Energy on your Boat

The concept of energy is likened to water for the easiest understanding. A bucket of water holds a specific amount of water that is measured in a number of gallons or liters. It is finite: when it is all drained out, it is gone. To gain more, it must be replaced from a water source.

In the same manner, energy is measured in a quantity like gallons or liters are to water. Energy quantity is measured in joules .  The battery itself is likened to the bucket. The battery holds a certain amount of joules of energy and when it is all gone, it is gone. To gain more usable electricity on your boat, you must add more joules back into your battery.

The concept of power is likened to a quantity of water flowing out of the bucket over time. While draining the bucket of water, the water is flowing out at a certain rate. If a 10-liter bucket drains out in 1 minute, the flow rate out is 10 liters per minute or 600 liters per hour.

Power is the flow rate or usage of energy over time measured in joules of energy per second of time. One joule of energy used every second is one watt of power . Thus, electrical devices are rated in watts – the amount of energy per second the device uses while it is ‘on’. The longer you leave the device on, the greater amount of energy is consumed and drained from your limited resource energy-holding batteries.

To summarize the above: Energy is a quantity, and power is the rate of usage of that energy over time.

When you are on a sailboat on a sailing vacation or cruising, you are the energy manager. As such, you’re going to need to understand the mathematics of it all and constantly do energy audits. When sailing at home, this is rarely an issue because typically at the end of the day you go back home and plug into the shore power to recharge your batteries. When sailing abroad or on extended trips, plugging into shore power rarely happens every night.

To put this all in perspective, a fridge/freezer unit on a sailboat is typically rated at 60 watts. This means that every second it is on and cooling it uses 60 joules of energy. But like a fridge at home, the fridge is not always running. It cools down to the right temperature then the thermostat switches the fridge off. When heat enters in through the walls of the fridge and raises the temperature a few degrees, the fridge turns back on and starts consuming 60 watts of power or 60 joules of energy every second to cool the fridge back down to its thermostat setting – then is switches itself off again.

Let’s say you load the fridge up with warm beer. After 1 hour of full running the fridge would have used:

60 j/sec * 3600 sec/hr  * 1 hr = 216,000 joules.

But that number, 216,000 joules really doesn’t mean much. So engineers simplified the concept using watt-hours , which is also a measure of energy (1 watt-hr =  1 joule/sec * 3600 sec/hr = 3600 joules). Since power (the flow rate of energy) is measured in watts, it is more practically meaningful to list energy in watt-hrs instead of joules. i.e. if you use 1 joule per second for 3,600 seconds you would have used 3,600 joules. Since one joule per second is one watt and 3,600 seconds is one hour this is 1 watt.hour (watt.hr). This is not watts per hour – there is no such thing – rather watt.hrs is the flow rate of energy (watts) multiplied by time (hours) and is thus watt.hours – a specific amount of energy used. In water terms, this is like liters/hour (akin to watts) multiplied by time (hours) – which is the amount of liters used.

Tip: Engineers use watt-hrs as the meaningful unit of energy

In this case, the 60-watt fridge/freezer ran for 1 hour and used 60 watt.hrs of energy from the house battery bank. If the fridge/freezer ran on full cooling for 24 hours then it would use:

60 watts x 24 hours = 1440 watt-hours of energy (or 1.44. kilowatt-hrs)

In reality, the fridge does not run 100% of the time (unless loaded with warm stuff). The % of time it runs is called the duty cycle. Assuming the duty cycle is 50% then a full day of running the fridge and keeping the beer (and food) cold consumes 720 watt-hrs or 0.72 kilowatt-hrs of energy.

Battery Capacity Ratings

Unfortunately, someone decided to measure lead-acid battery energy capacity in Amp-hrs . In reality, there is no unit of measurement as an Amp.hr and it drives engineers crazy. Amps need to be multiplied by the voltage to put it into real terms. For example, a 200 Amp.hr battery at 12 volts contains half the amount of energy as a 200 Amp.hr battery at 24 volts. So, Amp.hrs is really a nonsensical measurement of energy.

A more practical energy capacity rating of batteries is in watt.hrs. This allows anyone to easily calculate how long a battery will last at a certain wattage drain rate as the example above with the refrigerator. With the advent of Lithium-Ion batteries, fortunately, the ratings have now been universally listed in watt.hrs – whew. This makes the calculation of amount of available energy easy for the mariner.

How much energy?

We added up all the energy draws on a typical 40-foot boat with modern amenities. The conclusion was, on average, the boat will use about 5000 watt.hrs of energy per day – this is excluding air conditioning. This makes the math really easy – the 3,500 watt.hr Lithium-Ion battery above fully charged would provide 3500/5000 = 70% of the daily requirement.

When you add in air conditioning, the numbers go crazy. NauticEd performed an experiment on a Beneteau 41 monohull in Caribbean type conditions – 80 o F water temperature and 78 o air temp at night. The air conditioning thermostat was set at 75 o F. It was found that with 4 people sleeping onboard, the amount of energy consumed was 1,400 watt.hrs per hour. For a 10 hour evening using air conditioning, this means that 14,000 watt.hrs of energy would be consumed just for air conditioning. That is a lot: 4 of the lithium-ion batteries above!

Sources of Energy

Solar: Solar panels are conveniently and properly rated in watts – Joules of energy converted from sun energy per second to electrical energy. And actually, they are really rated in watts per square meter. The best solar panels today can produce about 300 watts per square meter. A big catamaran might have space for an array of about 6 square meters of panels (2m x 3m). This array can produce 300 watts/m 2 x 6 m 2 = 1800 watts. As a general rule of thumb, on a sunny day, you can multiply this by about 5 hours per day to gain the amount of energy produced. Thus a large array on a catamaran could produce up to about 9000 watt.hrs of energy. A monohull has significantly less available area for mounting solar panels and so 2 square meters is more realistic. This means 300 watt/m 2 x 2 m 2 x 5 hrs = 3000 watt.hrs per day can be produced from solar.

Thus while solar is capable of taking a big dent out of the energy used per day, if you add in air conditioning, solar can not keep up. You have to get more energy from other sources.

Alternator: An alternator does not produce very much energy despite it being connected to the engine. This is mostly because of the limited “dumb” electronics in the alternator such as the diode. An alternator will produce about 800 watts of energy. For every hour of engine run time, you only generate 800 watt.hrs which is not enough even if running the engine for 3 hours (2400 watt.hrs).

Generator : A generator onboard your boat can be a major source of energy. A typical marine generator that will fit on a 45-foot monohull provides up to 8,000 watts. This can keep up with the peak load of all air conditioners running at full speed as well as all your electronics. Generators are heavy and expensive to buy and operational maintenance is also expensive. Essentially, a generator is just another diesel engine that has an electrical generating device attached to it. It has soundproofing around it to lessen the noise, but if you’re running air conditioning from your generator, you’re going to be listening to the thrumb all night (as well as your neighbors).

High Output Alternators: Some alternators have been designed to output a large amount of energy as much as 3000 watts. However, these alternators have developed a reputation for being unreliable and often the diodes blow from surges of energy when throttling the propulsion engine up and down as you maneuver in a marina.

Intelligent Alternators (Integrel): Several attempts at smart alternators have been done which draw power off the front pulley via a large belt with a very stiff tensioner. One such is the Integrel device which NauticEd originally endorsed due to its innovation. However, Integrel has proven to be not reliable over time because of belt wear and breakage, high loads on the alternator bracket leading it to bend, as well as fatigue loads on the bracket bolts. Additionally, constant issues with the complex software lead to many installation problems costing many thousands of dollars to the installer and further ongoing operational problems to the user. The issue with Integrel really comes down to trying to pull too much energy off the front pulley. Consequently, the engine manufacturers have denied warranty coverage. Integrel is made by Triskel Marine in the UK – a small start-up company that did have a great idea but failed to implement it properly. Our advice is to stay away from the Integrel – there are other more innovative devices coming like hybrid engine/generators. See this article on why Integrel did not work .

Hybrid Engine/Generators: These are going to be seen more and more on sailboats and powerboats and seemingly are the ultimate solution.

The parallel hybrid system makes use of the high power available from the drive shaft driven by the diesel propulsion engine. Between the engine and the propeller, a smart clutch/gearbox is inserted. The clutch can send mechanical power to the propeller as well as to an electric generator. The electric generator creates electricity and stores it in a 48-volt bank of batteries for later usage. What is clever about this system is that the electric generator can double as an electric motor, so now if the 48-volt bank of batteries are full and the mariner decides to run their boat propulsion on electricity, they can switch off the diesel engine and allow the electric motor to drive the propeller through the clutch/gearbox.

The design below is supplied by Hybrid Marine

For further understanding on this particular product from Hybrid Marine , although there are other manufacturers out there. NauticEd has no relationship with Hybrid Marine and can not speak regarding their exact technology but does recognize that two major boat manufacturers, Antares Catamarans and HH Catamarans, are using their technology.

The 48-volt bank of batteries charged from the motor/generator also doubles as a large storage of energy for use onboard for air conditioners, refrigerators, and boat electronics, etc.

The smart mariner then just makes decisions about his stored electrical energy and runs the diesel or electric motor as appropriate. When at anchor, if there is not enough energy in the 48-volt bank, electricity can easily be made from the main engine through the electric generator.

This hybrid system completely eliminates the traditional generator which is just another diesel engine onboard with associated weight and cost. 

Using the hybrid system will allow the mariner to generate a huge amount of electrical energy very quickly and store it in Lithium-ion batteries. For example, if a catamaran uses 20 kW.hrs of energy for its air conditioning on a night, this amount of energy could be generated in 2 hours of dual engine run time as opposed to running a generator all night long. Add solar and you can cut that in half. Electrical energy can also be generated while using the spare available energy from the propulsion engines even while maneuvering in gear.

Wind Turbines: Manufacturers rate their turbines for 28 knots of wind speed. But power output from wind turbines decreases by the 3rd mathematical power with wind speed. So if you half 28 knots to 14 knots, an impressive-sounding 400 watt rated wind turbine can only produce 50 watts.

Water flow generators: As water flows over the propeller while the boat is sailing which turns the propeller. This can be harnessed into electrical energy. Many hybrid systems as above have this capability built into their system. While this adds to your incoming energy, it relies on you sailing (a lot).

Inverters and Converters

An inverter is not really a source of energy on your boat. It changes electric stored energy in batteries into 110 vAC or 220 vAC (alternating current) energy. AC is what your larger appliances run on such as a microwave and is the same as you have in your house. Thus to run AC appliances from your batteries, you need an inverter. Inverters are rated in watts (the amount of watts should be greater than the appliances you want to connect).

You can get a large inverter that is permanently mounted into your boat for running such devices as microwaves or a smaller portable inverter that will create a small amount of 110v/220v current for charging laptops and the like.

Similarly but opposite, a converter converts AC electricity into DC electricity. An example is the battery charger which takes electricity from the shore power or from the generator and uses it to charge the batteries. Additionally, a converter can change one DC voltage to another DC voltage – e.g. 48vDC down to 12vDC.

And just for completeness, a transformer changes from one AC voltage to another – e.g. 220vAC down to 110vAC or 110vAC up to 220vAC. You find these on boats that are world cruisers moving between continents and countries.

Running out of energy on your boat sucks. It will mean warm drinks, food going off in the warm refrigerator, navigation equipment going down, and worse. The prudent captain will monitor and manage energy usage just like drinking water on the boat. Training your crew to be energy conservative is a good idea. Air conditioning is the biggest energy drain so try to use natural cooling like wind scoops.

Lithium-Ion batteries are a technology gift to the marina but efficient ways of topping up those batteries need to be considered such as solar and hybrid engine/generator systems.

My vision for NauticEd is to provide the highest quality sailing and boating education available - and deliver competence wherever sailors live and go.

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Types of Sails for Sailboats: A Comprehensive Guide

by Emma Sullivan | Jul 28, 2023 | Sailboat Racing

Short answer types of sails for sailboats:

Sailboats typically use four primary types of sails: mainsails, genoas/jibs, spinnakers, and staysails. Mainsails are the largest and provide forward propulsion. Genoas/jibs enable efficient sailing upwind. Spinnakers are used for downwind sailing and maximizing speed. Stay-sails provide stability in heavy wind conditions.

Understanding the Basics: Different Types of Sails for Sailboats

Sailing is not just a passion but a way of life for many people. Whether you are an experienced sailor or just starting out, understanding the different types of sails for sailboats is essential to navigate the vast seas. In this blog post, we will delve into the basics of sail types, their functionalities, and how they can enhance your sailing experience.

1. The Mainsail: Starting with the star of the show, the mainsail is the largest and most important sail on a sailboat. It is typically positioned behind the mast and provides primary propulsion when sailing upwind or reaching across different wind angles. With its triangular shape, it catches wind efficiently and drives the boat forward like a well-oiled engine.

2. The Genoa or Jib: Next in line is the genoa or jib sail (pronounced ‘jīb’) that complements the mainsail perfectly. Positioned at the bow, it adds extra horsepower to help propel the boat forward even faster. The genoa sail offers versatility by allowing adjustment to different wind conditions without compromising speed and agility.

3. The Spinnaker: Often called “the wild card” among sails, spinnakers come in vibrant colors and are usually used for downwind sailing situations. When deployed, this balloon-shaped beauty fills with air like a parachute, harnessing every ounce of wind power available – perfect for exhilarating rides in light breeze conditions. However, handling a spinnaker requires skill as it can become untamable when winds pick up speed!

4. The Storm Sail: Just like its name suggests, storm sails are designed specifically for rough weather conditions – think rainstorms and gale-force winds! Smaller in size compared to other sails on board, these heavy-duty wonders provide stability during adverse weather situations by ensuring that sailors stay safe while navigating through treacherous waters.

5. The Gennaker: A combination of genoa and spinnaker, the gennaker is a true hybrid sail. Perfect for reaching and running downwind, it comes in handy when you want to sail at higher speeds without dealing with the complexity of managing a traditional spinnaker. Its lightweight nature and ease of control make it an excellent choice for both racing enthusiasts and leisurely cruisers alike.

Now that we’ve covered some key types of sails, it’s important to note that each sail type has various designs within its category. These designs cater to specific sailing conditions, such as heavy winds or light breezes, ensuring optimal performance during your time on the water.

Before wrapping up, let’s briefly touch on the importance of choosing the right sails for your sailboat. The type of sail you select can significantly impact your sailing experience – from optimizing speed and maneuverability to ensuring safety while exploring new horizons. Therefore, consulting with experienced sailors, researching different options, and considering factors such as boat size and intended use are crucial steps in making an informed decision.

In conclusion, understanding the basics of different types of sails for sailboats is vital for anyone stepping into this exciting world. From the powerful mainsail to the versatile genoa or jib, each sail plays a unique role in enhancing your sailing experience. So whether you’re looking to set out on lengthy ocean crossings or simply enjoy peaceful coastal cruises, knowing your sails will help you navigate every nautical mile with confidence and style!

Choosing the Right Sail: A Step-by-Step Guide to Types of Sails for Sailboats

Welcome to our blog where we will embark on a sailing adventure and explore the intricate world of sail selection. Choosing the perfect sail for your sailboat can seem like a daunting task, but fear not! We are here to break it down step-by-step and help you navigate through the vast sea of options. So grab your compass and let’s set sail!

Step 1: Assess your Sailing Style Before diving into the ocean of sail choices, it’s important to identify your sailing style. Are you a casual cruiser who enjoys leisurely trips across calm waters? Or do you yearn for thrilling high-speed races under challenging conditions? Determining this will play a vital role in selecting the most suitable sails for your needs.

Step 2: Consider Sail Material The material used in constructing sails significantly impacts their performance and longevity. Traditional woven Dacron sails are cost-effective, durable, and ideal for recreational sailors. However, if you’re an avid racer or prefer enhanced performance in varying wind conditions, composite laminated sails might be worth exploring.

These advanced sails utilize lightweight materials like carbon fiber or Kevlar, providing exceptional strength-to-weight ratios that optimize speed and maneuverability. Just keep in mind that these high-performance sails often come with a higher price tag.

Step 3: Understanding Sail Shapes Sail shape directly affects how efficiently your boat harnesses wind power. Depending on your sailing intentions, different shapes offer distinct advantages:

a) Bermuda Rig: This popular triangular mainsail design is commonly found on cruising boats due to its versatility. It offers easy handling and adaptability to various wind angles.

b) Gaff Rig: If you appreciate traditional aesthetics combined with robust downwind performance, gaff rig may satisfy your desires. Its distinctive four-sided configuration enables larger sail area while maintaining control during gusty conditions.

c) Cat Rig: Designed for simplicity and ease of use, cat rigs feature a single mast and sail, usually located at the front of the boat. This setup is excellent for beginners or those seeking a straightforward sailing experience.

Step 4: Size Does Matter Now that we’ve covered shapes let’s discuss the importance of sail size. Sailboat sizes can vary significantly, ranging from small dinghies to massive ocean-crossing yachts. Matching your sail size to your boat’s specifications ensures optimal performance and safety on the water.

Factors such as wind conditions in your local area, desired speed, and crew abilities must also be considered when determining the ideal sail size.

Step 5: Seek Expert Advice When in doubt, enlist the knowledge and assistance of professionals in the sailing community. Local sailmakers or experienced sailors can provide valuable insights catered specifically to your needs. They possess a wealth of firsthand information regarding local conditions, popular sails within your sailing community, and potential upgrades that could elevate your sailing experience.

So there you have it! A step-by-step guide to choosing the right sails for your sailboat. By assessing your sailing style, considering materials and shapes, properly sizing your sails, and seeking expert advice, you’ll be well on your way to embarking on unforgettable voyages atop glistening waves.

Remember that selecting the perfect sails for any sailor is ultimately an art as much as a science – enjoy exploring this exciting world while keeping safety and performance at heart!

Frequently Asked Questions About Types of Sails for Sailboats

Welcome to our blog where we aim to provide you with detailed, professional, witty, and clever explanations on frequently asked questions about types of sails for sailboats. Whether you are a seasoned sailor or just starting your sailing journey, understanding the different types of sails available is crucial for maximizing your boating experience. So, let’s dive in!

1. What are the different types of sails commonly used in sailboats?

Ahoy! When it comes to sailboat sails, you’ll often encounter three main types: mainsails, headsails (also known as jibs), and spinnakers. Each serves a specific purpose and contributes differently to the overall sailing performance.

– Mainsails: The largest and most important sail on a boat, mainsails are primarily responsible for propelling the vessel forward. Positioned behind the mast, they generate power through their large surface area and can be adjusted using various controls like boom vangs and cunninghams.

– Headsails/Jibs: Located at the bow of the boat, headsails come in various sizes such as genoas or jibs. Jibs are generally smaller than genoas but offer better maneuverability in heavier winds. These sails help balance the forces acting on the boat by providing lift from the front.

– Spinnakers: For those seeking exhilaration on reaching or downwind courses, spinnakers are a must-have! These big billowy sails catch wind from behind and enable higher speeds. Used in lighter winds when sailing off course or downwind, they can turn an ordinary sail into an extraordinary adventure.

2. Which type of sail should I use during upwind sailing?

When battling against the wind while navigating upwind (or close-hauled), it’s essential to hoist your headsail/jib rather than relying solely on your mainsail. This combination allows for efficient airflow diversion around both sides of your boat – creating that sought-after lift required to sail efficiently and beat upwind.

3. Are there any sail types specifically designed for downwind sailing?

Absolutely! For a fantastic downwind experience, you’ll want to unleash the power of a spinnaker. These beautifully large sails are uniquely shaped to capture every gust of wind from behind, propelling your boat at exhilarating speeds. But beware, handling a spinnaker can be quite challenging, so practice and caution are vital.

4. Can I use more than one headsail on my sailboat?

Ahoy mates, this is where it gets exciting! Sailors often employ multiple headsails simultaneously for enhanced maneuverability and increased propulsion. Known as “sail combinations,” common setups include using both a jib and genoa together or even deploying two genoas with different sizes at once – affording great control options in varying wind conditions.

5. How do sails differ in shape and material construction?

Sails come in various shapes and constructions tailored for specific purposes. The materials used range from traditional woven fabrics like Dacron (popular for its durability) to high-performance laminated fabrics such as Kevlar or carbon fiber composites (offering increased strength but potentially at higher costs). Each material has its advantages, so it’s crucial to choose the right sail based on your sailing goals, preferences, and budget.

So there you have it, sailors – an informative yet entertaining rundown of frequently asked questions about types of sails for sailboats. Remember that selecting the appropriate sails depends on numerous factors like wind conditions, desired speed, boat size/type, and personal preference. Now go out there, catch the wind in your sails, and embark on unforgettable nautical adventures!

Exploring the World of Main Sails: An In-Depth Look at Types and Features

Title: Exploring the World of Main Sails: An In-Depth Look at Types and Features

Introduction: Welcome aboard, fellow adventure-seekers! Today, we embark on an exhilarating journey into the enchanting realm of main sails. As sailors, we understand the pivotal role that these magnificent pieces of cloth play in driving our vessels forward. So, let us unfurl our curiosity as we delve into the vast expanse of main sail types and features. From traditional designs to cutting-edge innovations, fasten your seatbelts or rather hoist your clew lines; for it’s time to set sail on this epic exploration!

Main Sail Types: 1. Bermuda Rig: This timeless and widely used design originates from Bermuda (hence the name) and showcases a triangular shape with a pronounced mast incline. Known for its versatility and effectiveness across various wind conditions, the Bermuda rig offers superb control while maintaining desirable speed.

2. Gaff Rig: Picture a charming vintage schooner gracefully sailing across crystal-clear waters under an expansive gaff-rigged main sail – pure nautical bliss! Here, a wooden spar called a gaff supports the top edge of the sail, allowing for easier manipulation during maneuvers without sacrificing performance.

3. Lateen Sail: Embark on an exotic journey to distant shores with the lateen sail adorning your vessel. Hailing from ancient maritime civilizations such as Egypt and Phoenicia, this triangular sail is rigged with its base along one side of the boat—a sight that effortlessly evokes captivating tales from seafaring lore.

4. Junk Rig: Pay homage to centuries-old Chinese traditions by embracing a junk rig main sail configuration – perfect for those who crave a taste of both beauty and functionality in their sailing escapades. With multiple battens enhancing structural stability while reducing stress on individual components, this unconventional yet ingenious setup unlocks exciting possibilities in terms of ease-of-use and adaptability.

Main Sail Features: 1. Battens: These slender, lightweight rods serve as key components within a sail, improving its shape retention by preventing unwanted fluttering and enhancing overall efficiency. Modern main sails often boast battens made from sturdy materials like carbon fiber or fiberglass for optimal durability.

2. Luff Systems: Achieving precise control of the leading edge of the main sail is crucial to maximizing performance. Here, the choice between traditional hanks or convenient luff slides and cars comes into play – seamlessly balancing heritage with modernity while enabling ease of reefing and tweaking for swift adjustments.

3. Headboards: Crown jewels atop our main sails! These structures reinforce the upper portion, ensuring longevity by distributing stress during rough weather conditions. Ingenious evolution has given rise to lightweight alternatives such as carbon-fiber headboards that offer exceptional strength while minimizing weight aloft.

4. Reefing Mechanisms: Navigating formidable seas sometimes calls for reducing sail area to maintain stability and safety onboard. With various reefing systems at our disposal, like slab reefing or in-mast furling, we can swiftly decrease the main sail’s size while retaining ultimate control over your vessel’s destiny!

Conclusion: Ahoy fellow adventurers! We have traversed uncharted territories on this voyage through the enchanting world of main sails—unveiling their mesmerizing types and navigating their irresistible features along the way! Whether you favor tradition or embrace innovation with open arms, it’s clear that every sailor possesses unique preferences when it comes to these majestic fabrics that propel us forward into breathtaking oceanscapes. So, hoist your favorite mainsail high and let winds carry you toward endless horizons as you embark on extraordinary maritime exploits!

Jib or Genoa? Unraveling the Differences in Types of Headsails for Sailboats

When it comes to headsails for sailboats, there are two popular options that often leave sailors scratching their heads: jibs and genoas. Understanding the differences between these two types of headsails is crucial for making informed decisions on the water. So, let’s weigh anchor and set sail into unraveling the mysteries behind jibs and genoas.

Starting with the basics, a headsail is any sail set forward of the mast, aiding in propulsion by capturing wind energy. Now, onto our contenders – the jib and genoa!

A jib is traditionally defined as a headsail that is smaller than 100% of a boat’s foretriangle – that triangular area between bow, mast, and forestay. This compact size allows for enhanced maneuverability and responsiveness in challenging wind conditions. Jibs come in various sizes, including the storm jib (ideal for heavy weather) and the working jib (perfect for moderate breezes). If you’re aiming to finesse your way through tight spots or swiftly navigate crowded marinas, a jib might be your trusted mate.

On the other hand, we have our vivacious challenger – the genoa! Unlike its smaller cousin, a genoa spans beyond 100% or even up to 150% of a vessel’s foretriangle. Picture an oversized butterfly wing gracefully caressing through the air. Genoas provide tremendous power when sailing upwind or reaching under lighter wind conditions due to their substantial surface area.

Now you may ask yourself: “Why would I need all that extra canvas flapping about?” Well, dear sailor, here’s where physics enters our nautical narrative! A larger sail area means more lift generated by airflow over its surface. This added lift helps counteract heeling forces caused by wind pressure on other sails (mainly your mainsail), thereby improving stability and reducing strain on both crew and rigging.

But beware! With great power comes some caveats. Handling a genoa can be quite daunting when winds pick up or narrow channels beckon for precise maneuvering. Its increased size may hinder boat agility and make tacking (turning into the wind) a delicate dance with unpredictable results.

Ultimately, your choice between a jib and genoa depends on several factors: sailing style, prevailing weather conditions, crew size, and boat design. For spirited sailors seeking fast-paced thrills or seasoned racers trying to outpace competitors, the performance of a genoas’s extra sail area unquestionably tickles their fancy.

Meanwhile, those leisurely cruising along calm waters might favor the nimbleness of a jib that effortlessly responds to steering inputs.

Remember, dear sailor – understanding these trade-offs allows you to harness the wind more effectively. So weigh your options wisely before hoisting your favorite headsail type atop its lofty perch!

In conclusion, whether you opt for a diminutive jib or embrace the allure of an expansive genoa, each headsail brings its own unique sailing experience. Just like choosing between a swift steed or a graceful partner in dance, finding the perfect match requires careful consideration – for it is this match that will carry you across vast oceans or whisk you away to secluded coves. Ahoy!

All About Specialty Sails: Discovering Unique Types for Specific Wind Conditions

Sailing is not just a sport or hobby; it’s an art that requires skill, precision, and a deep understanding of the elements. One crucial factor that can make or break your sailing experience is the type of sail you choose. Just as different brushes serve various painting techniques, specialty sails are designed to address specific wind conditions. In this blog post, we will dive into the depths of specialty sails, exploring their unique types and unveiling the secrets behind matching them to specific wind conditions.

1. Battened Mainsail: Let’s start with one of the most common specialty sails used in sailing – the battened mainsail. This sail is equipped with long, lightweight battens that run parallel to its leech edge, enhancing its ability to maintain shape and stability. Suitable for light winds and cruising situations, the battened mainsail ensures optimal control even when gusts try to play tricks on you.

2. Genoa: When it comes to flying through moderate winds with grace and speed, every sailor worth their salt knows about the mighty genoa. This specially designed foresail boasts a larger overlapping area compared to a jib and can adapt seamlessly to various wind angles without compromising maneuverability. Whether you’re racing or embarking on an adventurous voyage, having a genoa onboard will give you that extra oomph!

3. Spinnaker: Are you craving adrenaline-pumping downwind rides? Then look no further than the spinnaker – often referred to as a “kite” due to its distinctive shape and vibrant colors! This asymmetric sail is made for strong winds blowing from behind your vessel’s beam or even dead astern. Its massive size catches every gust available, propelling you forward in exhilarating bursts over endless blue waters.

4. Storm Sail: Mother Nature holds many surprises up her sleeve, including unexpected storms that can leave even the most experienced sailors feeling like novices. This is when a storm sail comes to the rescue. Made from heavy-duty material and featuring a smaller hoist, this compact sail keeps you safe, stable, and in control when strong winds threaten to overpower your vessel.

5. Code Zero: Meet the ultimate weapon for light wind sailing – the code zero. Ideal for symmetrical or asymmetrical layouts, this specialty sail offers exceptional performance in extremely light wind conditions. Its distinctive design allows it to harness even the slightest breeze with minimal drag, effortlessly propelling your boat forward when other sails would hang limp.

6. Gennaker: Imagine combining the best of both worlds – the speed and power of a spinnaker with the ease of use of a genoa. Enter gennakers! Perfect for those cruising days where optimal performance is paired with user-friendly handling, these specialized sails bring joy to sailors looking for an all-around solution in moderate wind situations.

The world of specialty sails goes far beyond what we’ve explored here today, but this overview should give you a taste of their fascinating variety and purposefulness. These unique sails are meticulously crafted by experts who understand not only their complex aerodynamics but also how they interact with different wind conditions to unlock your vessel’s true potential.

So next time you embark on a sailing adventure, take into consideration the specific wind conditions you may encounter and make sure to equip yourself with the right specialty sail that will turn your voyage into an extraordinary experience worth cherishing. Happy sailing!

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MAIN FUNCTIONAL REQUIREMENT:   Propel a boat with or against the wind

DESIGN PARAMETER: Airfoil (the sail)

A BIT OF HISTORY:

Square Sails 3000 BC - 900 AD

• Wind Force + Drag Force = Boat Mass * Acceleration. The wind force overcomes the drag force of the boat.
• Drag Force = Water Pressure * Keel Area + Air Pressure* Exposed Boat Area Most of the drag is due to the keel moving through the water. The sails, lines, mast, crew and cargo also add wind resistance.
• Wind Force = Wind Pressure* Sail Area. The greater the wind pressure and the greater the area of the sail, the greater the wind force.

Lanteen/Triangle Sails 900 AD

DOMINANT PHYSICS:

BERNOULLI'S EQUATION

Edmund Bernoulli theorized in 1738 that under certain conditions , one can the energy in a fluid system is constant.

P + 1/ 2r V^2 + gh = C

P = Fluid Pressure [N/m^2] r = Fluid Density [kg/m^3] V = Fluid Velocity [m/s] g = Gravitational Acceleration Constant [N/m^2] h = Height [m]

Bernoulli's principle may be applied to when a fluid flows outside the boundary layer. The flow must furthermore be modeled as incompressible, steady, and frictionless.

(Put Bernoulli airfoil picture in here)

Usually, one can assume the gravitational effects are negligible compared to the magnitude of the increase in VELOCITY which results in a DECREASE in PRESSURE. The streamlines separate at the leading edge of the airfoil and meet again at the trailing edge. The pressure above is LOWER than the pressure below, creating a LIFTING FORCE.

The other lift theory for is based on EULER'S EQUATION.

EULER'S EQUATION

    dP/dn = r V^2/R

P = Fluid Pressure [N/m^2][psi] n = Normal Vector to Curved Streamline r = Fluid Density [kg/m^3] V = Fluid Velocity [m/s] R = Radius of Curvature of Streamline [m]

The air pressure above the airfoil along a NORMAL VECTOR from the wing surface is inversely proportional to the distance from the RADIUS OF CURVATURE. At a certain distance above the airfoil is AMBIENT air pressure. The pressure INCREASES from the center of curvature along the normal vector until it reaches ambient pressure. The air pressure closer to the airfoil thus must be LOWER than the ambient pressure. Again, the pressure above is lower than the pressure below and a LIFTING FORCE is created.

For more on airfoils and lift, see How An Airfoil Works by Mealani Nakamura and How Hydrofoils Work by Tina Rosado.

HOW DOES LIFT SAILBOATS USE LIFT?

When the boat sails "into the wind", the bow is pointed into the APPARENT WIND, which is the vector resolution of the TRUE WIND and the BOAT COURSE.

The SAIL in the wind acts as an AIRFOIL and the HULL in the water acts as a HYDROFOIL, so there are two sets of forces acting on a sailboat: AERODYNAMIC and HYDRODYNAMIC

AERODYNAMIC FORCES

(insert aerodyn forces )

There are two ways to examine the aerodynamic forces acting on the boat.

• The DRIVING FORCE is the thrust that moves the boat along its course.
• The HEELING FORCE is perpendicular to the course. It spills wind, decreases speed, and tips the boat.

The goal is to maximize the driving force. However, as the driving force increases, so does the heeling force. The sailor makes a compromise between speed and stability.

• The low pressure over the curved sail creates a crosswind LIFT force.
• Viscous and pressure effects result in DRAG opposite the motion of the boat
• The LIFT and DRAG may be resolved into a TOTAL AERODYNAMIC FORCE (AF).
• The angle e a between the LIFT and the AF is the AERODYNAMIC EFFICIENCY, a measure of speed.

  Cot e a = L/D.

HYDRODYNAMIC FORCES

• The curved surface of the hull creates a HYDRODYNAMIC SIDE FORCE (SF), which balances the aerodynamic HEELING FORCE.
• The water pressure over the cross-sectional area of the keel creates a RESISTANCE (R).

A large SF increases STABILITY, but is proportional to the resistance, which reduces SPEED.

• These two may be resolved into a TOTAL HYDRODYNAMIC FORCE (HF).
• The angle e h between the SF and HF is the HYDRODYNAMIC EFFICIENCY, a measure of stability.

Cot e a = SF/R

HOW DO SAILORS MAXIMIZE BOAT EFFICIENCY?

The angle between the boat course and the apparent wind direction, b, is the boat's ANGLE OF ATTACK.

b = e a + e h.

The angle between the sail CHORD LINE and the wind direction, a is the sail's ANGLE OF ATTACK. If the sail points straight into the wind, there will be no airfoil shape, and no lift. The sail must be slightly angled The largest speeds are obtained while sailing as close to the wind as possible, while the sail chord is approximately co-linear with the boat's centerline. The sailor must turn the boat to follow the course, but alters the sail position (lets the sail out) to maintain the sail's optimum angle of attack.

The sailor may also change the sail's shape for changing wind speeds.

A thick airfoil generates more lift, but also more drag. If you subscribe to Bernoulli's theory, the increases are due to the higher velocity and lower pressure. If you prefer Euler, the lower pressure is due to the smaller radius of curvature . For the same reasons, a thin airfoil generates less drag, but also less lift.

The sail is "kept tight" in the shape of the thin airfoil at moderate to high wind velocities. Large lift is coupled with large heeling and the boat may tip over. When the wind speed is low, the sail is "let out" a bit to generate more lift, and thus more driving force. However, if the sail is let out too much, it will luff and force the boat away from the wind.

LIMITING PHYSICS:

None Submitted

PLOTS/GRAPHS/TABLES:

WHERE TO FIND SAIL BOAT:

On the water!

REFERENCES/MORE INFORMATION: Airfoil and Hydrofoils

Marchaj, C.A. Aero-Hydrodynamics of Sailing . Dodd, Mead & Company, 1979.

Evans, Michael E. MSME. Email from January 13, 1998.

Perdichizi , Richard. Senior Technical Instructor, Massachusetts Institute of Technology Aerodynamics and Astronomics Department. Conversation on January 14, 1998.

Energy sources on Mini 6.50

Finnish sailing yacht Fuga collaborates with PowerUP

A guide to powering your sailing boat.

Energy for navigation, refrigeration, lights, or other electrical items requires a reliable power source on any sailing boat or yacht. Depending on the desired luxury and convenience of the boat, energy consumption may vary greatly. Powering your sailing boat is not the simplest task.

If you have an engine, it’s possible to charge the batteries. But a boat’s engine will use almost as much fuel to charge batteries as it does when motoring. Idling your engine still produces emissions and pollutants that negatively affect our environment and health. Running your engine purely for charging batteries can also harm it, as it is not designed to run below its rated level.

Before choosing which energy system is best for your needs, you first need to establish:

• What are you trying to accomplish (power navigation, run refrigeration, etc.)?
• How much electricity do you require?
• Do you need to modify your boat’s electrical system to meet those requirements?
• Do you have the weather conditions (wind, sun, etc.) to “fuel” the generator?

Let’s review the different energy generation and storage sources of boats and yachts.

STORAGE OF ENERGY

Batteries are required to store the electrical energy received from the generator or other sources to dispatch it depending on electrical devices demand. The batteries provide a real-time and on-demand reply to your boat electrical requirements.

Marine batteries are designed specifically for use on a boat, with heavier plates and robust construction designed to withstand the vibration and pounding that can occur onboard. For this reason, marine batteries are usually more expensive than automobile batteries, which can tempt some boat owners to purchase an auto battery instead of a marine battery. Don’t make that poor decision. A marine battery will last longer and be more reliable than an auto battery in a boat.

There are several types of batteries available. The main ones are:

• Open lead-acid batteries , the most common and oldest technology for cruising sailboat. The electrolyte fluid level has to be checked on a regular basis.
• Sealed lead (or lead-calcium; valve-regulated lead-acid VRLA) batteries require less maintenance due to the fact that no liquid level check is needed. The chemical reaction ensures battery operation for the lifetime indicated by the manufacturer.
• AGM and gel batteries . The liquid electrolyte is replaced by a gelled solution, there is no risk of leakage or liquid level issue, the performances are higher and the lifetime is better. But this type of batteries are heavier and more expensive.
• Lithium-ion batteries . Lithium batteries have a high specific energy density, which allows them to store more energy in batteries of smaller size and mass. They are also distinguished by high current output and have a number of advantages. But even their charge lasts for a very limited time. The major constraint to their development is a high selling price.

You should choose your marine battery based on the purpose of the battery:

• Marine starting batteries provide quick but powerful spurts of energy over short periods of time and are designed to start the engine and be rapidly recharged by the engine alternator. A starting battery should not be used for trolling motors or powering appliances.
• Marine deep cycle batteries are designed to discharge slowly over a long period of time and to withstand several hundred charging and discharging cycles. A deep cycle battery is the right choice for powering an electric trolling motor and other battery-powered accessories such as audio systems, a windlass, depth finders, fish locators, and appliances. Deep cycle batteries should not be substituted for starting batteries.
• Marine dual-purpose batteries combine the performance of starting and deep cycle battery and are a good choice on smaller when there’s no room for two batteries. While they’re able to perform the tasks of a starting battery and deep cycle battery, they’re not as efficient as separate batteries.

GENERATION OF ENERGY ON THE SEA | CHARGING

During sailing, the batteries need to be charged. It is a good idea to have at least two independent energy sources. In general, all methods of autonomous charging can be divided into two groups:

• Renewable energy sources (solar panels, wind, hydro generators, hydrogen fuel cell generators)
• Fossil-fuel powered sources (diesel generators, petrol generators, etc)

A renewable source of generation is a good option and a good safety backup for boats. There are several types of systems you can use for powering your sailing boat, including wind generators, solar panels, water generators, or a combination. Some systems can keep your battery fully charged while your boat sits on the trailer, on a mooring or at the dock, or can be used during long journeys while you are underway.

Let’s go through the renewable sources one-by-one.

•    SOLAR PANELS

Solar panels can be used on small and large boats effectively, they weigh relatively little, and can be flexible. But there are also many risks, especially for a small yacht. Primarily the risk of damage to the panel itself, controller, cable or contacts. The second is the lack of sun. It may happen that for several days the sun does not shine, or you go in such courses that you cannot effectively direct the panels to the sun – they stay in the shade of the sails.

On a positive note, they require minimal maintenance, don’t make noise, last up to 25 years or more, and are safe. In general, solar panels are a good complement with some other solution to produce electricity.

Solar sails (solar cloth sails) are being made around the world, where photovoltaic film is attached to each side of the sail.

•   HYDROGENERATOR

Water-powered generators are relatively inexpensive but require a flow rate to give charge. There are two main types: towed spinner generators and shaft generators. With both, however, a minimum speed of 4 knots is recommended, as below this speed, the energy generated is negligible. At low speed of the boat, there is no charge, but there is resistance. There is also a risk of damage – collision with floating objects and breakdown of the propeller. Plus, the risk of damaging of cables, charger and contacts.

•    WIND POWER

Wind generators use the apparent wind to produce renewable electricity through an alternator. They can be fixed on a mast or gantry. Wind generators have the potential to produce power 24 hours a day whether sailing or at anchor. If there is a strong wind, or you are underway, they can usually put out more current than solar panels. Wind generators, however, can be noisy, require regular maintenance and have the potential danger of rotating blades. Because of the huge sails of a sailing boat and long booms it is easy to mechanically damage such a generator.

•    METHANOL FUEL CELLS

Methanol fuel cells have good advantages – they work quietly and rather economically. They can be located inside the yacht and continue to work with any wind conditions and sea state. They don’t require too much special care while operating, but they do fail sometimes. Although we listed methanol fuel cells as renewable energy source, they do emit some carbon dioxide.

•    HYDROGEN FUEL CELLS

One of the most promising technologies for boats and yachts – hydrogen fuel cell generators. They are a relatively new, progressive energy source that run on renewable fuel. In principle, in the future, hydrogen could be generated even on board the yacht itself, increasing the autonomy. Of course, there are some big limitations that must be overcome, as the electrolysis process is relatively inefficient. Among the advantages – hydrogen fuel cells are lightweight and compact systems that provide a high charge current (the   UP400 model gives 32 A). It works in extreme conditions, is quiet and provides clean energy without emissions.

NON-RENEWABLE SOURCES

There are non-renewable sources available and quite often they tend to be more friendly for your wallet. Of the advantages, fossil-fuel generators can charge rather quickly. But more often than not, this is where the pros are over. This energy source is the least environmentally friendly of all. It runs on fossil fuels, has a very unpleasant exhaust, from which the head constantly hurts. It does not work while boat is heeling or bumping. Read more about the advantages and disadvantages of diesel generators  here .

Whether you are long-range cruising folk or enjoy the weekend getaway on a boat, energy is a sensitive topic for all boats. You get what you pay for, so consider your options carefully and it’s always best to consult an expert.

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What Type Of Energy Is Utilized To Power Sailing Boats?

Sailing boats have been around for centuries, and they are still a popular form of transportation and recreation today. While modern sailing boats may look different than their predecessors, they still rely on the same type of energy to power them: wind.

Wind is the primary source of energy used to power sailing boats. This is because it is free, renewable, and can be harnessed with relatively simple technology. The most common way to capture wind energy is through the use of sails. Sails are designed to catch the wind and convert it into forward motion, propelling the boat forward. This type of propulsion requires no fuel or other external sources of energy, making it an ideal choice for sailing vessels.

In addition to sails, some sailing boats also utilize auxiliary engines for propulsion when there is not enough wind available. These engines are typically powered by diesel or gasoline fuel, but some may also use alternative sources such as solar or electric power. However, these auxiliary engines are usually only used in cases where there is not enough wind available to power the boat on its own.

Overall, wind remains the primary source of energy utilized to power sailing boats today. It is free, renewable, and can be harnessed with relatively simple technology such as sails. Auxiliary engines may also be used in cases where there is not enough wind available to propel the boat forward on its own. Regardless of what type of engine a sailing vessel uses, however, it will always rely on the same source of energy: wind.

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Types of Sails: Explained

While all sailboats rely on wind, the types of sails used can vary greatly based on weather and craft type!

The reason for all the different types of sails is important to understand. Depending on the time of day and location of the water body, you might experience varying weather conditions. The sail acts like a motor, propelling your sailboat forward. The performance depends heavily on wind conditions. Different sails work to navigate weather conditions to maximize your performance.

In this article, we’re going to look at the most common types of sails found on sailboats.

• A mainsail is the most commonly-used sail.
• The gennaker is a cross between the genoas and spinnakers.
• A popular sail used in sailboats is the headsail/jib.

It’s important to know that various sails pose different dangers when it comes to strong winds, which is why knowing which to avoid or use is extremely helpful. Here we discuss the different types of sails and when to use them.

Types of Sails

Let’s look at the most common types of sails here.

1. Mainsail

Most sailboats have a mainsail . It’s the most commonly seen sail on boats and the first thing you think of when you think of sails. The mainsail is attached to the mast behind the boom, so it’s easy to keep an eye on since it occupies a lot of space.

Regarding incoming winds, mainsails have a large surface area, mainly due to how they are mounted on the boom.

Due to their large surface area, they do not require powerful winds to propel a sailboat forward. As the mainsail position is easily adjustable using the boom, you can reach all points of sail. 

2. Spinnaker

Due to the large dimensions and vivid colors of spinnakers, they are considered one of the most whimsical sails you can use. The sails are also often balanced, making them more suitable for reaching various points, including the sail’s running point.

Sails of this type are lighter, unlike genoa sails attached to the mast (see below). The spinnaker is not attached to the forestay , but stretches past the boat’s bow.

A spinnaker’s broad surface makes choosing the right conditions for use even more critical. When the wind is too strong, you and your passengers can be seriously injured by deploying this sail. This is why you should only deploy a spinnaker in calm conditions such as low winds.

A genoa is a sailboat with a genoa sail attached. The genoa sail is similar to a headsail, with large jibs mounted on the forestay. Compared to a normal headsail, a larger genoa sail partly or completely covers the main sail behind the mast. 

A genoa sail is used when there is light to moderate wind or when your sailboat is mostly in dead run sailing (with the wind blowing directly behind).

A genoa sail with such a large surface area is best in low-wind conditions. If you don’t, you’ll be moving very fast, which can lead to a potentially dangerous situation if you’re not careful.

4. Gennaker

Since 1990, gennaker sails have been a more recent sail type on sailboats. Gennakers are sails that resemble both genoas and spinnakers. They are larger than genoas but have a different shape from a spinnaker, unlike genoas and headsails, which are attached to the forestay.

To take advantage of lighter winds, sailors invented the gennaker without resorting to a spinnaker if the wind was strong. Overall, regarding a sail’s performance, a gennaker sail bridges the gap between genoas and spinnakers by taking advantage of relatively softer winds while allowing a greater range of motion.

5. Headsail/Jib

Headsails, or the jib, are second in popularity among sailboat sails. In most cases, it goes with the mainsail, the most common type. 

Generally, the headsail hangs over the boat’s bow on a sailboat. The sizing is often smaller than the mainsail.

You can especially benefit from a smaller headsail when a strong wind blows. As a result, you won’t want to use the main sail (or trim it heavily) to move more slowly and avoid being thrown around. The smaller the sail, the less wind it catches, so it doesn’t propel your boat as effectively as a larger one.

It is extremely important to have a good headsail, regardless of how wild or unpredictable the seas are.

6. Drifter Reacher

A drifter is a sail designed for light wind conditions, and they are larger genoas that can only be used in light weather conditions. Compared to a genoa, it has a larger sail area that increases performance downwind. It is primarily made up of nylon, which is a synthetic fiber.

7. Code Zero

Racing fans love these sails. Code zero sails have large genoas that overlap the mast heavily. The gennaker is roughly 200% larger than a regular jib and resembles a spinnaker and a gennaker combined. This sail is flatter than most. The design does not resemble a balloon, so it allows for better close-reaching, which makes it faster and easier to maneuver.

Common Types of Sailboats

A sloop is a classic sailing vessel with a single mast and two sails. A headsail may be a variety of jibs attached to the mast forestay and extends to the mast cap.

A sailing boat with multiple masts with several sails. Schooners have tall aft masts and can have as many as six masts.

The boat is easy to cruise with due to the cutters and two forestays capable of storing two headsails and varied sail points for varying wind conditions.

Fractional Rig Sloop

Fractional riggers sail sloops differently because their forestays don’t reach the mast top. The sailboat’s headsail occupies a fraction of the sail area, so less wind is captured, so the sailboat moves slower.

A ketch has a mast similar to a sloop, so its mainsail and headsail can reach up to the forestay. There is also a smaller mast positioned right between the stern of the boat and the mainmast. 

Cats have one mast and one sail, similar to dinghies. You can find the sailboat mast at the bow.

Sails are essential to the performance of your sailboat. Using the correct one for the water and weather conditions is important for success out on the water! You can become a more competent and knowledgeable sailor by understanding the common types of sails and mast configurations. 

After reading this article, we hope you will feel more comfortable in your sea skills. The danger levels associated with different sails also vary according to the strength of the wind, making it essential that you know what to look out for.

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Type Of Sails: A Complete Guide

Table of Contents

Last Updated on September 29, 2023 by Boatsetter Team

If you are approaching sailing and sailboats from a very beginner’s perspective , then the concept of different kinds of sails can be a strange one. We often believe we see one kind of sailboat with one kind of sail, and our simple minds lead us to believe you are only meant to move them around, and you will get to where you need to go.

However, you would not have landed on this article if you did not suspect that there was more to sails and sailboats. So here, you can have a kind of in-depth, kind of summarized review of the different kinds of sails and the most popular sail and mast configurations out there.

It is also important to understand why there are so many different kinds of sails. When you are out on the water, different weather conditions can occur. Your sail acts as a motor of some sort, moving your sailboat forwards, but your sail is also highly dependent on the wind conditions around it. This is why having different kinds of sails can help you navigate your weather conditions and turn them to your own advantage while sailing.

Different sails also come with different danger levels in case of strong wind, so knowing what kinds you might need to watch out for is also extremely important. So, without further ado, let us get into it.

You may have heard of this one before or seen it portrayed in movies and TV shows. As the name suggests, the mainsail is the most popular kind of sail on any sailboat, and they are found behind the mast. They are also attached to the boom. Because they take up so much space on your sailboat, they are also one of the most important sails to take care of and keep an eye on.

Since the mainsail is such a large sail, it does not require too strong a wind to propel it forward , as its large surface area will easily catch a breeze. At the same time, the fact that it can be moved around by moving the boom makes it, so it is easy to steer. This makes it so that the mainsail is the most important sail on your sailboat.

Headsail/Jib

The headsail, or the jib, is likely the second most popular kind of sail found on sailboats. This is because it often accompanies the mainsail, the most popular kind. On all sailboats , the headsail is put at the front of the mast over the sailboat’s bow . It is always a smaller sail than the mainsail.

The fact that the headsail is smaller can be especially useful if you are caught in strong winds. In this situation, you likely do not want to use your mainsail (or trim it as much as possible) to move slower and not be thrown around by the winds. Smaller sails catch less wind, meaning they do not propel your boat as strongly as larger sails.

Having a good headsail can be an incredible safety measure, especially if the seas you are trying to sail are known to be wild and unpredictable.

You may have seen a genoa sail before if you have been around boats or have ever lived in a coastal town. This kind of sail is a large sail that you can attach to the front of the forestay (similarly to the headsail). This is a larger sail than the headsail and can even cover the mainsail either partially or completely. For this reason, the genoa also used to be called an “overlapping jib.”

You should use a genoa if you are sailing through either light or medium winds and if your sailboat is at a dead run point of sail (this means that the wind is coming directly from the rear. If you attempt to use a genoa sail in stronger winds , you might start going too fast and put yourself and your boat at risk since it is such a large sail. So, it is  important to be careful .

The spinnaker is the most whimsical kind of sail since it is a large and colorful kind. They are also often symmetrical, which means they are more appropriate for reaching different points of sail, such as the running point of sail. They are lighter sails, and they do not cover the mast as the genoa sail does. You do not attach a spinnaker to the forestay and instead let it stretch out past the boat’s bow.

The large surface area of the spinnaker means that you have to be even more careful than with others on the kind of conditions you choose to use this sail in. If the winds are too strong, you could be putting yourself and your passengers at serious risk using this sail, so you should choose to use it only at times when the wind is low or in seas that are known for their low winds and tranquility.

As the name suggests, the gennaker sail mixes the genoa sail and the spinnaker sail. These kinds of sails are more recent inventions. They are as large as the spinnaker sail, but they are not symmetrical. Unlike the genoa or the headsail, they are also not meant to be attached to the forestay, like the spinnaker sail.

The usefulness of this sail is that if the winds change from a pure dead run to a reaching point of sail, then sailors do not have to resort to using a spinnaker from a genoa, instead of being able to  take advantage of different winds  while still using the same sail as they were before. This kind of sail is still only meant for lighter and milder winds , but there is more flexibility with the gennaker than the genoa and the spinnaker sails.

Popular Sail and Mast Configurations

There are many different ways to place the sails we have learned about in the above section. We have compiled a list of some of the most popular ones so you can understand how these sails can be used to make a sailboat move through the oceans.

A sloop is by far the most popular configuration. It features a single mast, double sail (the mainsail and the headsail), and mast configuration. The headsail is located from the forestay on the mast to the top of it. The type of headsail used can also vary from a genoa, a spinnaker, or a gennaker sail.

Fractional Rig Sloop

A fractional rig sloop also features a single mast with a double sail setup similar to a sloop. However, what makes the fractional rig sloop different is that the forestay does not reach the top of the mast. This means the headsail is constricted to a smaller amount of surface than on a regular sloop, making it so that your sailboat  captures less wind and moves slower .

Cutters are interesting because they’re like a sloop but with a second forestay. This can be useful because it allows them to carry two headsails (a mainsail and one of the jibs). Cutters are good for cruising because they offer a range of wind options, giving you more time to get from place to place.

This is a less common mast configuration than previous others on this list. This is because a ketch features two masts. There is a larger mast fit for the mainsail and the headsail and a smaller mast between the mainmast and the stern (the rear) of the boat. This kind of mast configuration is more commonly found among Northern European freighters or fishing boats. This mast configuration is also called the mizzen mast.

A schooner mast configuration features two or more masts. This is similar to the previous configuration, the ketch. It also features multiple sails. While a ketch’s aft mast (also known as the rear mast) is higher than the forward mast, a schooner’s aft mast is shorter than the forward mast. A schooner can also have up to six masts (although two are the most common). These are the main differences between the two.

This one is quite similar to a ketch mast configuration (mentioned above). The only real difference between them is that the mizzen mast is put directly behind the sailboat’s rudder post in a yawl.

A cat sail will have one mast and one sail. The mast is put at the bow of the sailboat. This kind of mast configuration is often found on smaller boats, more specifically on dingy boats. Boats with the cat mast configuration are also often called catboats.

Final Verdict

Having the appropriate kind of sail on your sailboat is incredibly important. At the same time, being aware of the kinds of sails that there are and the kind of sail and mast configuration can make you into a more well-rounded and informed sailor. With that in mind, we hope that you leave this article feeling more confident in your skills when you are out at sea.

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Sailboats - The Pros and Cons

PROS:  

Hold Your Own Power: Yes, most modern sailboats have an engine. However, that can be different than the dual-powered engines found on most powerboats. In a sailboat you hold the power while navigating, with slight help from the engine. This could be a pro or con depending on your ideal navigation vision and your willingness to learn everything involved with that level of control. If you want to be in constant control, a sailboat is more aimed toward your style. Environmentally Friendly: As we discussed earlier, most sailboats contain a single engine with low horsepower. For the most part, sailboats rely on the wind for power and movement, while the engine is mostly used for docking purposes. Although, it is possible to dock without an engine based on the tide and wind. These sailors are very impressive navigators.

Travel the World: If you’re lucky enough to travel the world and want to do so via the water, a sailboat is the only way to go. A sail can take you anywhere, making a sailboat the ideal craft for traveling long distances. Not to mention the money you’ll save on airfare and hotels.

  Save Money on Engine Upkeep: A sailboat’s engine is much smaller and is used far less compared to a powerboat. This keeps maintenance and fuel costs down.

Peace and Quiet: A sailboat is much quieter than a powerboat. Without the ongoing engine roar, the captain is able to socialize more easily, and the overall ride is much quieter. The only sounds are from the water, wind and snapping of sails.  

--------------- 

Wind Reliant: This can be seen as a positive or negative based on the situation. Although you are technically in more control of the vessel, you are still reliant on the wind. If the weather isn’t cooperating, sailing can become difficult fast. The best plan is just that, to make a plan. Always look at the weather ahead of time and schedule your adventure accordingly. 

Deep Drafts: A sailboat sits deeper in the water. With most of the hull underwater, it makes it more difficult to navigate a sailboat in shallow waters or near the shore.

Experience: You definitely need more training to operate a sailboat. It takes time to understand how the sail works and how the wind and tide will affect navigation. Owning a sailboat requires more education and practice.

Expenses: Replacing and repairing equipment on a sailboat can get expensive. Sails should be replaced after around 4,000 hours of use and rigging every ten years or so. Both items are pricey. 

Time and Energy Consuming: A powerboat requires the turn of a key and an occasional turn of the steering wheel. A sailboat, on the contrary, requires constant attention and adjustment, between the sails, steering, and weather.

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