monohull sailboat with foils

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Figaro BENETEAU 3

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Key Features

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The Figaro BENETEAU 3 is the first production foiling one-design monohull ever created. It is a distillation of technology and innovation, the result of a collaboration between some of BENETEAU’s best experts and the Van Peteghem Lauriot-Prévost (VPLP) office, the architects of the last two boats to win the Vendée Globe.

The prototype has been tested and the production of the boat has been launched. It will enter the ISO/World Sailing design category A.

Naval designer : Van Peteghem – Lauriot Prévost

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THE ADVENT OF A NEW STANDARD

MODERNITY, RELIABILITY AND PERFORMANCE

The specifications define the FB3 monohull as being as reliable as its predecessor, the FB2. It is equipped with foils, a better-performing, ballast-free hull, a more slender and deeper keel, a setback mast and a more extensive, larger sail plan.

Contrary to Imoca 60 foils, the Figaro BENETEAU 3 foils have an inward-facing profile. The way they operate is different. They are versatile foils that create drift reduction and improve the boat’s righting moment, without increasing the movement, which improves the boat’s performance.

Deep, with a straight blade, it creates minimum drag. Supplementary drift reduction is provided by the foils.

Made of foam sandwich, fibreglass and polyester-infused resin, it corresponds with current designs and is ballast-free.

MAST AND SAIL LAYOUT

Similar to the Imoca 60s, the mast is set back, providing balance under sail. This allows the use of high performance sails and the addition of a bowsprit. Solo sailors will sail with a square-top mainsail, a genoa, and a jib, but also a masthead spinnaker (105 m² (=125 yd²) to gain speed in a light breeze) and a small gennaker.

Mainsail area: 39.5 m² (420 ft²)
Jib area: 30.5 m² (323 ft²)
Large spinnaker area: 105 m² (125 yd²)

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The information below is intended for general informational purposes only and is subject to change without notice and does not constitute a contractual agreement. Any descriptions, representations, or statements made in this document are not to be considered binding unless explicitly stated otherwise in a formal contractual agreement.

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A3 / B4 / C6

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America's Cup - Dan Bernasconi explains the foiling AC75 - Part 1

Professional BoatBuilder Magazine

A bénéteau with foils.

By Dan Spurr , Mar 20, 2018

The newest iteration of the one-design composite Figaro Bénéteau 3 is a 32 ‘ (9.75m) high-performance sloop with port and starboard curved foils that improve lift and stability. The boat was designed by multihull specialists VPLP Design for La Solitaire URGO Le Figaro, a multi-port race along the French and Spanish coasts.

Followers of extreme sailing may know of Bénéteau’s several-year program to develop a production monohull with foils. Well, let’s qualify the term foils. The new 3 2 ‘ (9.75m) Figaro Bénéteau 3 does not rise out of the water like a Moth dinghy or multihulls on T-foil appendages installed on the centerline of the hull; instead, it has C-shaped port and starboard foils that increase lift and improve stability, while still retaining a deep, narrow-chord keel blade and ballast bulb. Bénéteau is jazzed, calling it “the world’s first production foiling monohull.” The concept resonated with members of the European yachting press, who chose the Figaro Bénéteau 3 as the European Yacht of the Year 2018 in the Special Yacht category.

The VPLP design was commissioned as a one-design for a specific event, the 2019 La Solitaire URGO Le Figaro. (For more on the French design firm VPLP, which specializes in long-distance monohull and multihull racing yachts, see Professional BoatBuilder No. 91.) This coastal multi-port event in France and Spain will mark the 50th anniversary of its running. The first, in 1970, was called the L’Aurore, after the sponsoring newspaper; in 1980, Le Figaro newspaper bought L’Aurore , and the name was changed. Later spon sors modified the name yet again; the word Solitaire refers to the singlehanded requirement of the event. The French love long-distance solo sailing in its many forms, including nonstop racing around the world. La Solitaire is regarded as a sort of training ground for the longer and more dangerous races, affording amateurs the opportunity to test their skills and talent for fund-raising. Price for the first 50 Figaro Bénéteau 3s was recently announced at the relatively modest €155,000 ($191,925). After that, the price jumps to €175,000 ($216,690).

In 1991 race organizers selected Group Finot to design the one-design boats, and Bénéteau to build them. A new design was created in 2003, and now a third one. The course and the four ports change each year, usually covering 1,500–2,000 nm along the coast of France and usually one other country, such as England, Ireland, or Spain. Time at sea is about 10–13 days.

Bénéteau has established a racing team that among other duties will oversee construction of the latest design at the old Jeanneau plant in Nantes-Cheviré. Bénéteau’s Julien Ferre tells us that reinforcements are “multiaxial glass webs with polyester resin” and, “all the structural elements are made in DIAB PVC 80-kg foam in infusion.” Bénéteau partnered with several subcontractors, including Multiplast (see PBB No. 90), which made the retractable carbon fiber foils. Ferre says, “The port and starboard [foils] are independent. There is a position to sail upwind and a position to sail downwind. In the inside position, the foil stays inside the Bmax value. There is also a rake forward/backward to adjust the incidence of each foil.” Bénéteau’s general manager, Gianguido Girotti, elaborated: “The idea is to make sure that when in use, they exploit at maximum [beam] the righting moment effect, and once closed, they do not [exceed] the beam of the [hull].” That way, mooring and road transport are easier without having to remove the foils.

The deck, with hardware installed, is lowered onto the hull with bulkheads in place. Note the opening in the topsides for the port foil.

Figaro’s foils, built by Multiplast (Vannes, France), are totally rigid, though adjustable for different points of sail.

Principal specifications: LOA 10.85m (35 ‘ 9 “ ), hull length 9.75m (32 ‘ ) , LWL 9m (29.5 ‘ ) , max beam 3.4m (11.2 ‘ ) , waterline beam 2.4m (7.9 ‘ ) , draft 2.5m (8.2 ‘ ) , displacement 2,900 kg (6,400 lbs), ballast 1,100 kg (2,400 lbs), sail area main and jib 70m 2 (753 sq ft).

Bénéteau, Gaëlle Violleau, tel. +33 (0) 251605204, website www.beneteau.com .

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Published on February 20th, 2017 | by Editor

Foiling in the Monohull Stream

Published on February 20th, 2017 by Editor -->

Something that seemed ‘out there’ just a few years ago is now making its way firmly into the mainstream. It is also winning yacht races. In the March issue of Seahorse magazine , Gordon Kay has an update on DSS state of the art.

With the monohull world increasingly embracing foils it seems timely to reflect on some of the lessons learnt over the past year and how 2017 and beyond look for the impact of DSS and for the other foil solutions in the 2017 marketplace..

While dramatic footage of semi-flying or flying yachts gets the headlines it is the background story that is perhaps more significant. In 15 years of developing, engineering and supplying DSS foils and installing them on various yachts we have never had a failure beyond the cracking of one foil, quickly identified as a failure by the builder to build the hull exit bearing surface as drawn. It is therefore quite thought-provoking to see the failure level in some other avenues of foil development.

The problems suffered by the Imoca class, particularly in testing, have been significant, not limited to foils in the water but to the windward foil as well (echoing issues the big tris experienced when ‘over-stiff’ ama construction led to failures through wave impact on the windward float).

(There have also, in passing, been a great many – unpublicised – foil failures during testing for this year’s 35th America’s Cup. However, this is a different situation where lightweight constructions are consciously being explored and tested to the ultimate limit. Still, it does confirm that this is a complex area of development when the best engineers and designers in yacht racing still have to place more than a little reliance upon good old trial and error.)

Safety and reliability have always been the watchwords in our development of foils at DSS. If it was not going to work reliably or safely then we could not see the point of investing heavily in R&D and practical testing. It will not always be possible to get a client to write endless cheques to cover ‘development’, or if it is then the class will go the way of the Orma 60s and others.

So we stand at a key point in the development of foils within the industry; it is no longer the preserve of the lunatic fringe, and it is crucial that future development needs to prioritise safety and reliability.

Modern history 2016 began with the Welbourn-designed DSS Quant 23 winning its division in the European Yacht of the Year awards. The first fully flying keelboat for production, and designed to be very much the everyman design that would allow a new generation, young and less young, to fly in safety and without the need to swim if it all went wrong.

Hugh Welbourn’s flying scow, the Quant 23, uses a curved foil to achieve essentially the same lift effect as is enjoyed on the Infiniti 46 with its straight DSS foils. However, in the case of the Quant the result is full flight in just 8-10kt of breeze. Compared with the Imocas, the Quant benefits from a keel fin to resist leeway, dispensing with the Imoca’s large foil tips. But the similarities, especially between the little foiler and Hugo Boss, are evident. Yet there is still a huge amount to learn, particularly in solving the Imoca puzzle with its rule constraints. Hugo Boss’s 24-hour record was, ultimately, only 2nm better than François Gabart managed four years ago without any foils at all…

To date 10 Quant 23s have been sold, and with the original Q23 now on Lake Garda and available for all to try, more and more people have seen what is available without spending a king’s ransom and requiring America’s Cup levels of skill.

The launch of the Infiniti 46 offshore racer, again Welbourn designed, caused a few raised eyebrows and comments when she first arrived in Europe in May, particularly with respect to the ability of such a boat to sail to its IRC rating.

Class wins and podiums in the Rolex Middle Sea Race and then the RORC Transatlantic Race, all with a Corinthian crew, demonstrate that perhaps the rating office might have been closer to the mark than the armchair experts.

What has been more interesting has been the amount learnt in the 10,000 miles of sailing in 2016 that the first Infiniti 46 has now completed. Zero structural failures, zero foil issues, zero issues with foil exits and, interestingly, zero UFO strikes…

We have always built our foils with Dom Pedron of Isotop and to date they have all been engineered by either Gurit or Will Brooks and, so far, they have all performed to expectation.

An interesting fact taken from the Infiniti 46 is that while the displacement of the yacht is 5,500kg, the foil exits are engineered for 9,500kg of load. Conservative? Probably, but avoiding failure as far as one can through a little extra diligence just seems smarter than saving a gram or two, with the consequential risks, as seen with some of the failures in the Imoca 60 fleet.

Another interesting launch was the prototype FLO1 from Aeronamics. A dinghy that flies but is not a Moth, and as with the Q23 is designed to introduce the averagely capably sailor to an easier and safer flying experience.

As 2016 drew to a close two larger projects emerged. First the CQS, Ludde Ingvall’s inspired reincarnation of his previous yacht, expertly handled by Brett Bakewell-White and launched a few weeks before the Rolex Sydney Hobart Race – making it to the startline against all the odds. That process was bittersweet for us, as the DSS foil itself, built in Vietnam, failed early in the race, having shown glimpses of the performances we have come to expect; with just a few days of sailing with the foil prior to the race there is much to learn. 2017 will no doubt be an interesting year of development for this team, with an all-new boat also in the air…

Finally, we completed our collaboration with Farr Yacht Design on the creation of a new 40m+ fast-cruiser that is now under construction. The process of due diligence took over six months with exhaustive studies of various foil geometries – necessarily in conjunction with different interior layouts. Details are still under wraps but we expect this yacht to demonstrate the same strong performance relative to its conventional peers as the Infiniti 46.

In terms of market appeal, according to our clients not everyone prefers the final designs from a previous generation.

And ratings… The rating story persisted throughout 2016 and into 2017, which will also see updated ratings for retrofits such as the Reichel-Pugh 60 Wild Joe. Faced with the challenge of a single-figure rating for allcomers, IRC have given a great deal of thought to how best to address DSS when rating the boats. Clearly, when executed intelligently, like most yacht designs, these boats can sail to their rating; what has been identified as undesirable is fitting foils that are not particularly effective or have a limited range and then asking IRC or ORC for a rating credit to ‘help’.

There are no rating credits for poorly designed rudders or keels so the same should apply to the foils and how they make up the overall balance and performance of a yacht.

We have conducted many studies internally and with both Farr Yacht Design and Brett Bakewell-White, plus comparison routeings with navigator Ian Moore, and while there is no silver bullet it is clear you can no longer dismiss DSS when you are considering an offshore/coastal programme, be it ORC or IRC focused.

We continue to work closely with the rating authorities, with both poacher and gamekeeper reasonable bedfellows as we look to provide confidence for owners who wish to move forward, while the rating managers ensure that their current fleets remain competitive… (Strangely the best sailed and prepared boats still seem to do well regardless of configuration).

2017 will bring more DSS ratings to the fore and so more performance data with which to validate the rating numbers.

Imoca 60s Bittersweet also best describes our experience within this class so far and this is where a history lesson is perhaps appropriate. In 2008 Hugh Welbourn and DSS were approached by Alex Thomson Racing to look at the possibility of collaborating with Finot-Conq in incorporating DSS into a new design for the next Vendée cycle. The base boat was not suitable so we declined; an opportunity missed.

Vendée Globe yacht design… in a nutshell. Five of the latest-generation Imoca 60s, including Banque Populaire (left), were committed to similar VPLP/Verdier designs when Alex Thomson (shrewdly) pressed the button with the sixth… Hugo Boss (right). Thomson’s boat used a simpler, more DSS style of horizontal foil than her foiled rivals; but as significant is that with extra dynamic righting moment his team ‘risked’ a slightly narrower hull – which contributed to some devastating pace downwind and in light air. Thomson powered away from the fleet on the opening leg, at times sailing 2-3kt faster

However, work on other Open 60 proposals led us towards slimmer, lighter design concepts using DSS as the starting point, which in hindsight may well have turned a well-established fleet on its head. At the same time we opened discussions with the Imoca class, and eventually DSS did end up being accepted… but with an expensive sting in the tail.

A single transverse ‘traditional’ DSS foil would be counted by Imoca as two of five allowable moveable appendages; assuming a traditional wide hull requiring twinrudders, plus canting keel, then any foil solution would now need to deliver dynamic lift and increased righting moment (RM) plus enough sideforce to resist leeway.

In the end a complex hybrid solution with an assortment of vertical tips became the norm for the most recent VPLP/Verdier designs, but these brought into focus the risks – and costs – of introducing complex angled sections into highly loaded composite boards (a pair of typical Dali foils will set you back €300,000–350,000 plus).

Effectively then, these boats had put their eggs very much in one basket – side force and RM all combined in one item, with the failure risk increased with the tip additions. Hit something with a relatively straight, flattish foil and the shock loads fore-and-aft can be designed for… hit something just with one of those long tips and suddenly you are also dealing with torque loads on the inner foil and cassette that are much harder to resolve accurately.

Not surprisingly, the phonecall came in from ATR early in 2014. One of their in-house technicians had been working with Infiniti Yachts on a 30m project for Danish Yachts before joining ATR and had had plenty of sea time on the Infiniti 36 and our 27ft test boat and so was well informed as to DSS and its potential.

‘What are your thoughts on a DSS-type 60 to the current Imoca rules…’ So Hugh ran some comparisons which demonstrated that, executed properly, significant gains could be made over both the existing fleet and the new designs we were then aware of. Hugh and Will Brooks developed several design options, which to our eye looked normal but in the context of superwide Imoca 60 world the boats did look quite radical! We then provided ATR with some basic lines and a couple of appendage configurations which went into the Qinetiq tank for evaluation; soon afterwards we learned that ATR had opted to sign an agreement with VPLP for their new boat.

However, the story did not quite end there. ATR asked: ‘Would we collaborate with VPLP?’

So we arranged to take VPLP sailing and ATR chartered the first Infiniti 36 for a number of months. We arranged further tests with the ATR team on DSS boats and generally headed in the right direction. Sadly, while all was well during the sailing trials, back on land matters of exclusivity between DSS and ATR started to creep in and ultimately the working relationship ended. However, the information and thoughts that we had already shared could hardly be unlearnt, but clearly we had done enough to convince them that foils were the way forward.

If nothing else, even with some of the starboard foil broken off, Hugo Boss did at least prove to be the fastest Imoca 60 in the Vendée Globe. Encouragingly for us, the boat that Alex took around the world was also indeed narrower and lighter than the similar but not identical new boats of his French rivals, moving closer to the design tested at Qinetiq.

The Vendée design directions are very clear – the race is usually decided on the run down the Atlantic and being first boat into the Southern Ocean systems. Ice limits then corral the boats into narrow strategic options riding the weather systems around the bottom, and finally around the Horn after which it is a case of protecting your position – far from easy when passing through the Doldrums and dealing with the complex weather on this final stage of the course. So the slimmer, lighter, more easily driven option scores heavily here on the Vendée course matrix – add in the pace from fully utilising foils in the design and it’s a no-brainer. Or at least it should be.

Whether through lack of insight and/or just a lack of confidence in a new technology, or simply timing, the other five new Imoca 60s all featured ‘standard’ fatter hulls with added Dali foils of varying configurations, that could revert to standard configuration if the experiment failed.

Although they are quicker than the previous non-foil generation, the speed of the slightly slimmer Hugo Boss implies that five very expensive recently built yachts may already be past their prime. It would also have been interesting to see PRB’s time without her own keel problems.

The technical conclusion seemed clear. With two foils Hugo Boss was demon – strably quicker than any other yacht in the class; in particular the undesirable ‘crashing and about to crash’ operating mode of the Dali is softened, with a DSS-style foil plus narrower hull making for higher sustainable average speeds.

As the 2016/2017 Vendée Globe reached its conclusion it was interesting to read in Seahorse that some Imoca designers are already thinking about the next generation of narrower designs, something we have been doing for some years.

Nor, it seems, has the DSS effect been lost on the wider market as we already have interest in new designs to move the game forward again in the Imoca class.

Anything but DSS? As we move from the lunatic fringe into the mainstream DSS is increasingly being accepted. We have technical partnerships, licensing agreements and design arrangements with companies building boats from 4.5m to 40m plus. Farr Yacht Design, McConaghy Boats, Seair, Mer Forte, Bertrand Design, Infiniti Yachts, Quant Boats, Brett Bakewell-White, Aeronamics, Baltic Yachts and a few others we cannot talk about are proving the appeal of DSS across a wide spectrum.

The price of the DSS licence fee is oft discussed but we feel it is fair, particularly when one considers it is a one-off cost that equates to a couple of sails. For an Imoca 60 at the time we were in discussions the licence was €50,000. The cost for one set of Dali foils was, as mentioned, up to €350,000, then you break a few, develop a few and before long it is almost real money. The complete package for the DSS retrofit of the 60ft Wild Joe, including all costs is significantly less than half that of one set of Dali foils… in a new build it would be even less.

Does DSS really work? DSS foils have been proving themselves for some years now and continue to do so. Whether you want an IRC pocket rocket, a gentleman’s daysailer or a fully flying keelboat DSS has delivered, first time, out of the box, without a failure – not very exciting, but sometimes boring is good.

Inevitably ‘not invented here’ is something we have to address from time to time. Indeed, one client was advised by a leading firm of naval architects that fitting DSS would make his yacht unsafe – his question to us was, ‘hy did they say this?’

Our reply was that perhaps they did not want to lose him as a client. ‘Well, they lost me as a client,’ he replied.

In an industry where we are struggling to bring new people to the sport, and often struggling to retain even the people who already love the sport, how can we continue to take risks with the goodwill of the very people we rely on for an industry, the client? We need to tread carefully to bring a new generation to the world of foilassisted sailing.

But there are some worrying ‘foil developments’ being looked at elsewhere that may harm this gradual softening of resistance. Ever more complex arrangements – or proposed arrangements – have been sighted that can only ever be more expensive and less reliable in use. None of us needs to see things go backwards for the sake of costly efforts to reinvent the wheel. Failure always attracts more coverage than success. We all need to be mindful of that.

2017 New DSS projects for 2017 include more work in the fast cruising market in partnership with Farr Yacht Design for the Infiniti 50, 56 and 85 designs. The further adoption of DSS by Farr for their new 42m makes an ever more compelling case for DSS in this sector, where comfort and performance are the primary drivers but not traditionally the most comfortable of bedfellows. Less pitching, less heeling, more performance and shorter passage times are all high on every owner’s wish list.

We continue to work on DSS projects from 4m to 40m-plus whether flying or just cruising faster. Not all projects can be listed here sadly; however, they are all challenging and rewarding in equal measure.

Seahorse is the dominant international magazine for anyone serious about their racing. Take advantage of their subscription offer or order a single copy of Seahorse online at www.seahorse.co.uk/shop or for iPad download the Seahorse App at the iTunes store. Contact by email at [email protected] .

Tags: DSS , foiling , Seahorse

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The Foiling AC75

The mechatronics required to move the A75’s foils deliver precision handling and speed, and while they may look basic in form, their execution is anything but standard.

The physics of a foiling AC75 are as simple as they are complex, but envision a large windsurfing board with towering sails; there is no heavy keel to help keep it upright like a traditional sailboat. Wind blowing across the sails is the energy that essentially propels the boat forward while also making it lean over onto its side. Counteracting that heeling force on the AC75 is the boat’s subsurface horizontal foil, adjustable wings that provide lift for takeoff and steady flight.

On the opposite of the hull is the other foil arm, suspended by a massive hydraulic ram inside the boat. It’s weight helps to keep the boat balanced and upright while underway. When the boat tacks or jibes, battery-driven hydraulic rams push one foil underwater during the turn and then pulls the opposite into its up position.

Touchdowns are slow and, from what is known, take-off speed is king. Maneuverability comes next.

Under the rules of the regatta, all AC75s must meet certain dimension restrictions (length, width, weight, etc.), but the overall hull shape is left to the design team’s vision of what’s fast. There was noticeable variety in each team’s first-generation boats, common traits appeared with the second-generation designs: namely in the form of an underbody appendage that is said to capture airflow beneath the boat when foiling. Once a boat is foiling, however, the hull becomes an aerodynamic fuselage to carry the sailors controlling the boat.

Foil designs are open to development as well and that’s where the experts say the Cup will be won or lost. Teams are limited in the number of foil wings they can build for competition, but do have wide latitude to reshape them during the competition. Different wing profiles produce different results: larger wing foils get earlier liftoff in lighter winds (6.5 knots is the minimum required for racing), but come with drag. At the top of the wind range (23 knots maximum), smaller foil wings can and will be used, but here the tradeoff is speed versus control and maneuverability. The wings also have adjustable flaps and the internal mechanics of these adjustments are highly protected intellectual property.

Inside the AC75’s hull is an intricate web of hydraulic pumps, tubes, valves and rams that allow the sailors to make micro adjustments, using programmable logic controllers to manipulate the sails and foils on demand. Of the 11 crew members onboard, the division of labor is clear: the helmsman essentially steers the boat around the racecourse. The mainsail trimmer controls the three-dimensional shape of the mast and the mainsail, using a handheld controller with toggles and buttons to manipulate the sails and effectively balance the boat through every gust and lull in the wind.

The third critical crewmember in this modern-day afterguard is called the “flight controller” who uses custom controllers and software to move the big foil arms up and down, to alter their angles, and adjust the foil flaps. Essentially, these three individuals fly the boat, which leaves the eight others as pure muscle, powering the boat’s hungry hydraulic systems every time some presses a button. Nothing happens on these boats without hydraulic pressure, which is why the “grinders” will be heads-down, hammering away for 60-minute stretches on their pedestals.

length: 75 feet – 22,86m
max beam (width): 5m
mast: 26,5 m
sail area: mainsail/soft wing 145m2 – jib 80m2 – code zero 180m2
weight: 6500 kg
crew: 11 people
crew weight: 990 kg
ideal grinder weight: 105 kg
expected speed: upwind: from 25 to 38 knots downwind: between 32 and 50 knots (one knot = 1 mile per hour = 1,852m per hour)

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America’s Cup foiling monohull raceboat design revealed

The Defender Emirates Team New Zealand and the Challenger of Record Luna Rossa have revealed the first details of the design for the AC75 foiling monohull that will race in the 36th America’s Cup .

Challengers heading to Auckland in 2021 will have to master the art of sailing with twin canting T-foils, which can be lifted out of the water on the windward side to reduce drag.

What’s more, the wingsail design has been done away with in favour of a more traditional sailing rig. In a statement, the teams explained: “Whilst recent America's Cup multihulls have benefitted from the power and control of rigid wing sails, there has been no transfer of this technology to the rigs of other sailing classes.”

Safety and stability has been a key consideration and as a result the new AC75 raceboats able to self-right in the event of a capsize, while the foils can be folded under the hull to allow the vessel to fit into a standard marina berth.

It is hoped that this technology will filter through to cruising yachts in future and we have already seen the first evidence of this in the form of the Baltic 142 Custom foiling superyacht.

Grant Dalton, CEO of Emirates Team New Zealand, said: “Our analysis of the performance of the foiling monohulls tells us that once the boat is up and foiling, the boat has the potential to be faster than an AC50 both upwind and downwind.”

Patrizio Bertelli, chairman of Luna Rossa Challenge, added: “The choice of a monohull was a fundamental condition for us to be involved again in the America’s Cup. This is not a return to the past, but rather a step towards the future.”

British contender Sir Ben Ainslie , team principal and skipper of Land Rover BAR, gave his backing to the design, claiming that it will add to the growing popularity of the America's Cup .

"The sport has gained a lot of new fans and this boat, delivered with a global circuit and high-quality free-to-air broadcast TV will cement their interest in the America's Cup and build on a very strong base," he predicted.

This dramatic design has spent four months in development and will be refined further before the AC75 Class Rule deadline of March 31, 2018.

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The Lyncean Group of San Diego

The amazing america’s cup ac75 foiling monohull flying boat.

Peter Lobner, 25 February 2021

The first race of the 36 th America’s Cup racing series starts on 5 March 2021 in Auckland, New Zealand. The defending Emirates Team New Zealand and the challenging Luna Rossa Prada Pirelli Team will be sailing (or rather flying) a radical new class of America’s Cup boats knows as the AC75, which is a foiling monohull that was designed from the ground up to “fly” on its foils. It isn’t clear if the AC75 is a flying boat or a sailing airplane.

The Luna Rossa Prada Pirelli Team won the right to challenge based on its performance in the Prada Cup match races held from 14 January thru 20 February 2021. The America’s Cup races are scheduled from 5 to 14 March 2021. You’ll find complete information on the races on the America’s Cup website at the following link: https://www.americascup.com

The New York Yacht Club American Magic entry, Patriot , was eliminated during the Prada Cup races, after recording no wins in the Round Robin series and no wins in the semi-final races against Luna Rossa . Patriot was damaged and in danger of sinking following a dramatic high-speed capsize following a tack in gusty wind conditions while leading Luna Rossa during Round Robin 2 Race 3 on 16 January 2021.

The AC75 operates with two completely different sets of boat dynamics:

Waterborne while accelerating at maximum power to quickly reach foiling speed at 12 – 14 knots
Flying on the foils to reach a top speed that can exceed 50 knots

Making a smooth transition from waterborne to flying on the foils can be a big challenge for the crew. As the transition is being made, the power demand drops rapidly (suddenly) as the hull emerges from the water and starts flying on the foils. The crew must quickly adjust sail power and trim to maintain control of the flying boat.

As you would expect, there are extensive regulations governing most aspects of the boat’s design. The Rule is explained at the following link: https://www.americascup.com/en/official/the-class-rule

To get an introduction to an AC75 boat and its primary components, you can view a 3-D model here: https://www.americascup.com/en/ac75

The AC75 is a very lightweight vessel, with a fully-loaded weight of 7,600 kg (16,800 lb). The empty weight, not including sails or crew, is limited to 6,520 kg (14,374 lbs.). Of that, 3,358.5 kg (7,403 lb) is supplied by, or specified by, the America’s Cup event organizer, and includes the following standard items for all teams.

Mast : A detailed specification; essentially a one-design mast with a D-shaped leading edge; teams can choose their manufacturer.
Rigging : Supplied to all teams.
Media equipment: Cameras, mounting hardware, power & controls supplied to all teams.
Foil cant arms and hydraulic control system : Standard system developed, tested and supplied to all teams by one manufacturer. The hydraulic system is powered manually by hand-operated grinders. The hydraulic system includes an interface to the trailing edge flaps on the foils supplied by each team.

Each team is responsible for designing and building the rest of the boat while remaining within an empty weight budget of 3,161.5 kg (6,968 lb). The primary areas for innovation by each team are the following:

Hull design: (maximum length 75 feet / 22.86 m), with the primary choice being a flat bottom or with skeg to provide a less sensitive transition between waterborne and foil borne modes.
Crew and hand-operated grinder placement
Twin-skin soft main sail: Forms a fabric 3-D airfoil
Single-skin soft head sails
Rudder + stern foil
Foil wings, fairing and active trailing edge flaps: These are mounted to the standard cant arms; foils must be symmetrical with a maximum span 4 meters; flaps control lift; total weight is limited to about 1/3 rd the weight of the empty boat.

There are many AC75 videos available online, including many covering the exciting Prada America’s Cup World Series races in December 2020 and the Prada Cup races in January – February 2021. These boats are so fast that the races are short and action packed. I’ve listed several videos focusing more in boat technology below.

I hope you’ll enjoy a few of the AC75 videos and follow the America’s Cup Races. It’s not like any yacht racing you’ve seen before.

For more information:

“The AC75 – The Technology,” Americas Cup: https://www.americascup.com/the-technology
Mark Chisnell, “Weighing in on the AC75,” Sailing World, 15 September 2020: https://www.sailingworld.com/story/racing/weighing-in-on-the-ac75/
Christopher McFadden, “The Engineering and Design Behind Modern Racing Yachts,” Interesting Engineering, 23 February 2021: https://interestingengineering.com/the-engineering-and-design-behind-modern-racing-yachts
“The AC75 | Designed to Fly” (7:25 minutes), America’s Cup, 2 August 2020: https://www.youtube.com/watch?v=VQUl_hf6yo8&feature=emb_logo
“America’s Cup – How Crews Handle Their AC75s” (17:41 minutes), Americas Cup, 24 January 2021: https://www.youtube.com/watch?v=o0bReWK_vsg
“Sea Wolves – The new America’s cup boat! AC75 Technology analysis/Deep dive special! Auckland 2021” (51:07 minutes), Sea wolves, (with an introductory review of Americas Cup history by Troy Sears, owner of the replica yacht America , which is home ported in San Diego, CA), 16 December 2020: https://www.youtube.com/watch?v=sjs76uHEqeM
“The American Magic Capsize – A Step by Step Explanation” (8:32 minutes), America’s Cup, 24 January 2021: https://www.youtube.com/watch?v=pXLUIouASdM

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Hydrofoils for Sailboats

By By Steven Callahan
Updated: July 29, 2020

Hydrofoils have been providing dynamic lift since fish sprouted fins. And people have been employing foils ever since they first put paddle to water, and certainly since adding keels and rudders to boats. But the modern, flying America’s Cup boats, kiteboards, Moth dinghies, shorthanded offshore thoroughbreds—these are all playing in a new world in which the terms “hydrofoils” or “lifting foils” describe those oriented to raise a hull or hulls from the water. In these racing realms, if you ain’t got foils, you ain’t got nothin’.

Lifting foils that allow these boats to sometimes home in on three times the wind speed might appear to be of little interest to cruising sailors, but with such common cruising features as self-steering and autopilots, self-tailing winches, rope clutches, fin keels and faster hull shapes all having been passed down from the racing scene, one must ask, “What promise, if any, do hydrofoils hold?”

Lifted or partially lifted boat patents extend back to 1869, but workable watercraft took roots along with early flight. Italian Enrico Forlanini began experimenting with foils in 1898. In 1906, his 1-ton 60 hp foiler reached 42.5 mph. Alexander Graham Bell’s HD-4 Hydrodrome flew on Bras d’ Or Lake at 70 mph in 1919. And several sailing foiler patents began appearing in the 1950s. Notably, JG Baker’s 26-foot monohull, Monitor, flew at 30-plus mph in 1955. Baker experimented with a number of foil configurations, and at least built, if not used, the first wing mast. The first offshore foiler was likely David Keiper’s flying trimaran, Williwaw , in which he crisscrossed the Pacific in the 1960s.

By the 1980s, numerous speed-trial and foil-enhanced offshore-racing multihulls showed huge promise, and have since evolved into behemoth trimarans clocking 30 to 40 knots continuously for long periods, not to mention the monohulls in the Vendée Globe (and soon the Ocean Race) that are capable of speeds exceeding 30 knots. But as boat designer Rodger Martin once reminded me, “If you want a new idea, look in an old book.” He was right. The fully foiling monohulls that will compete in the 2021 America’s Cup will bring things back full circle to the foiling monohull Monitor .

Fluid Dynamics Primer

Any foil—a wing, sail, keel, rudder or lifting foil—redirects the flow of fluid (air included), creating high- and low-pressure areas on opposite sides of the appendage, while developing lift perpendicular to the foil’s surface.

Advancements in foiling science is due in part to the hundreds of foil shapes that were tested, with tabulated results, by the National Advisory Committee for Aeronautics, the forerunner of the National Aeronautics and Space Administration. For the better part of a century now, aircraft and boat designers have been able to choose from a spectrum of refined foil sections that produce predictable amounts of lift and drag for known speeds of fluid and angles of attack, or the angle at which the foil passes through the fluid. Sections of efficient faster foils, as seen on jets or as we flatten our sails to go upwind or reach high speeds, have smaller nose radii and are thinner, with the thickest section of the foils farther aft, up to nearly halfway toward the trailing edge.

The most efficient foil sections at slow speeds are fatter, with the maximum thickness farther forward, and with larger nose radii, than faster foils. The angle to fluid flow or angle of attack also is greater. We see these slower foils on wings of prop planes and sails when off the wind or in light conditions.

Most sailors are familiar with traditional foils on boats, the teardrop sections of keels that produce lift to weather, reducing leeway, and of rudders, allowing them to steer. Even a flat plate can be a foil, but these tend to be inefficient. Such a shape is prone to fluid separation from the surface, meaning they stall easily, and they maintain poor lift-to-drag ratios. Even keels and rudders are somewhat lift-compromised because they are symmetrical and have to work with fluid coming from either side, whereas lifting foils are more like aircraft wings or propellers, with asymmetrical sections honed for performance in a more stable, fluid flow.

The point is, any foil can be employed at various angles to the surface to prevent leeway, produce increased stability, or help lift the boat out of the water. But those not required to work with fluid flowing from opposite sides can then be honed to maximize lift and minimize drag. Asymmetrical foils were used on boats like Bruce King’s bilgeboarders, including Hawkeye , back in the 1970s. And, designers, including Olin Stephens, had previously employed trim tabs behind keels to improve keel performance.

Sails, which are heeled airfoils, not only drive the boat forward, but they also produce downforce, actually increasing the dynamic displacement of the boat. To counter this and keep the boat sailing more upright, multihull designer Dick Newick first employed slanted asymmetrical hydrofoils in the outer hulls of his small charter trimaran, Lark , in 1962. A portion of the lift developed by the hydrofoil resisted leeway, while a portion worked to actually lift the leeward hull, keeping the boat more upright and reducing dynamic displacement and drag.

Anyone who has ridden on even a foil-stabilized boat will know how riding at least lightly on the waves, and especially above them, beats smashing through them. When boats lift off, everything gets a lot smoother, drag falls away, and the boat accelerates.

Cruising on Foils

But why would a cruiser want to whip over the sea? Wouldn’t this demand an inordinate amount of attention by the crew? Would lifting foils even be applicable to a boat that must have substantial displacement to carry crew and stores? Aren’t cruising-boat hydrofoils an oxymoron?

Maybe, but I believe our boats’ hulls are likely to sprout fins much as fish have as we orient foils to more efficiently resist leeway, add stability, aid steering, reduce drag, increase comfort, allow for shallower draft, and enhance wider variations in hull shapes.

Boats have gotten increasingly wide through the years to advance form stability, improve performance (primarily off the wind), and boost interior volume. But the downside is that fat boats tend to slam more upwind. What if you could reduce dynamic displacement of the boat and lift that hull even partially from the water? The result would be less slamming, especially upwind.

At the same time, what about narrower boats that are known for being more seakindly, especially when closehauled, but lack form stability to carry adequate sail area for powering upwind, and tend to roll badly downwind? Or shallow-draft vessels that are lovely for cruising, but again, tend to suffer from reduced stability? Foils can give that stability back.

Looking ahead, boat designers might choose to reduce ballast, making up for it with a foil. In short, lifting foils can reduce boat drag and motion while increasing power and performance.

Pitching also does no favors for speed or crew comfort. Foils can come into play here as well. Foils parallel to the sea’s surface resist motion up and down, and a lifted boat skating above chop also is less prone to hobby-horsing through waves. Multihulls have always been particularly susceptible to pitching for a number of reasons, but watching videos of multihulls sailing to weather show an obvious huge advantage that foilers have compared with nonfoilers. Offshore multihulls now routinely employ T-foils on the rudders to control the fore and aft angles of the boat (attitude), a feature easily adaptable to any vessel.

OK, so what’s the cost? Obviously, the more things sticking through the hull, especially if they are retractable, the more it’s going to impact the interior. There would be added weight, complexity and cost. Foils also create noise, and there’s susceptibility to damage from hitting stuff. And let’s not forget compromises with shapes, purposes and things not yet imagined.

As for damage, it’s possible to fold the foils back into the hull. Think swinging center- boards or actual fish fins. Daggerboardlike foils can at least employ shock-absorbing systems similar to the daggerboard arrangements found in many multihulls. This includes weak links that are outside the hull, so if a foil is struck, it frees the foil to fold back or to come off before being destroyed or damaging the hull. Or, foils might hang from the deck rather than penetrating the hull, allowing them to kick up (and to be retrofitted to existing boats). These configurations also relieve the interior of intrusions, and keep the noise more removed from it. I have no doubt that numerous talented designers will be exploring all kinds of options and compromises in coming years, finding ways to make foils both practical and more than worth the compromises.

Sailing more upright, shallower draft, speed, comfort—what’s not to like? Just what is possible? I have a feeling the cruising community is about to find out.

Steven Callahan is a multihull aficionado, boat designer and the author of Adrift , an account of his 76 days spent in a life raft across the Atlantic.

More: foils , How To , hydrofoils , print june july 2020 , sailboat design
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Foiling and Hydrofoiling: Everything you need to know

A foiling International Moth dinghy. Photo: Christopher Ison / Alamy

What is foiling?

Although foiling or hydrofoiling feels like a recent revolution to take the world of watersports by storm, it is actually much older than many appreciate.

In terms of motorised waterborne craft, the first foiler was a motorboat designed and built by Italian inventor Enrico Forlanini in 1906.

It did, however, take quite a bit of time before foiling boats with sails took to the water, but even then many people might be surprised to learn that even in the 1970’s the foiling trimaran, Williwaw, covered over 20,000 sea miles in and around the South Pacific all on its foils.

It turns out the history of hyrofoiling goes back further than many think.

It was not until the early-2000s that foiling really started to take hold, with a development dinghy class, the International Moth, leading the way.

Foiling boats

With huge amounts of interest in the 11ft Moth dinghy, foiling began to spread throughout the sport of sailing. And it was not long until hydrofoiling boats of all different shapes and sizes were taking the water.

Over time, some traditional classes converted to foiling – the A-Class and C-Class catamarans being examples. But more new boats were also designed specifically with hydrofoiling in mind.

In 2013 Emirates Team New Zealand built their 72ft America’s Cup catamaran to be a foiler, forcing their competition for the Cup, Oracle Team USA to convert their AC72 into a foiler to stay competitive – ultimately Oracle Team USA won the Cup in one of the biggest sporting comebacks of all time .

To date the America’s Cup has not looked back with the competition taking place in smaller hydrofoiling AC50 catamarans in 2017 and the newly conceived monohull foilers, the AC75 s, in 2021.

In 2021 the Olympics Games introduced the first ever foiling catamaran in the Nacra 17.

Foiling yachts

Offhsore, 90ft Ultime multihulls on their foils are competing to be the fastest to race around the globe and design houses across the globe are racing to create foiling yachts for the masses which could dramatically reduce cruising times from one destination to the other.

There are also many classes of yacht that are taking some of the lessons from fully foiling craft and putting them to use in a semi-foiling manner.

Here the biggest technical innovation is in the IMOCA60 class, which is famously used for the single handed non-stop round the world race, the Vendée Globe .

The latest couple of generations of IMOCA 60s have been build with huge, technologically complex foils to generate lift. These are powerful enough to lif the boats fully out of the water, but as yet the class rules do not allow for rudder foils which would stabilise flight and allow for full foiling.

Where sailing boats and yachts have, arguably led the way in the history of foiling over the past decade or so this has filtered down into a plethora of other watersports craft.

Although in the early days foiling was typically the preserve of elite sailors and watersports professionals, increasingly we have seen boats and boards designed to foil in the hands of the average sailor, surfer or windsurfer.

This race to bring the fun of foiling to beginners is continuing apace with beginner foiling boats, windsurfers, surfers etc. coming to the market every year.

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14 Best Monohull Sailboats

Last Updated by

Daniel Wade

December 28, 2023

Monohulls are among the most popular boats in the world accounting for over 75% of the total number of boats.

This means that choosing the best monohull sailboats for your sailing adventures can be overwhelming. Fortunately, we're here to help you by highlighting the best monohull sailboats.

Whether you're an accomplished sailor or just starting in the world of sailing, a monohull boat is an ideal option for anyone who wants a true sailing experience.

Unlike other types of sailboats, the level of adrenaline that a monohull brings to your sailing adventure is almost unmatched.

It doesn't matter whether the conditions are rough , wild, flat, or calm, a monohull is the perfect boat type for anyone looking for the thrills of the sail.

Unfortunately, you might not fully enjoy the thrills of sailing on a monohull sailboat if you do not choose the best monohull sailboat for you.

While a monohull cannot compete with multihull sailboats in terms of cabin size, anchoring closer to the shore, and comfort, it should hold its own if you are planning to spend more time at the sea and in unpredictable conditions. ‍

A monohull sailboat will definitely be an ideal option if you're planning to go to more challenging places. This is exactly why you have to make the right choice when looking for the best monohull sailboat.

Over the years, we've sailed many monohull sailboats and that's precisely why we feel confident that we can help you choose the best monohull sailboats.

We've gone through various designs and launches, tested them, and sifted through many monohull brands to select the best monohull sailboats that we strongly believe should be on your bucket list.

So without further ado, let's walk you through them.

Table of contents

Best Monohull Sailboats

For several decades, Amel 55 has not only been the epitome of easy downwind handling but has developed a cult-like following among sailors. It was designed as the successor to the legendary Super Maramu and brings to the fore incredible features that every serious sailor will value. From a sturdily built hull, solid guardrails to a skeg-hung rudder, watertight bulkheads, and lush bulwarks, Amel 55 is built with anything you could ever want in a perfect monohull sailboat.

And even with a list of standard features, this monohull sailboat is truly designed for those who want to live comfortably on a sailboat for long periods. It comes with superb sea berths with lee cloths, a dishwasher, crockery, an electric furling main and genoa, and several practical items that will make sailing very comfortable.

We have to admit that the design might look old going by modern standards, especially with the advent of easier sail handling systems. For example, the ketch rig design is no longer ideal and is out of fashion. But even with this downside, the Amel 55 remains a phenomenon; a legendary monohull sailboat that ticks all the right boxes in the sailing world.

2. Bavaria Cruise 46

Probably the most popular monohull sailboat in recent years, the Bavaria Cruise 46 is a formidable monohull sailboat that was voted "European Yacht of the Year" in 2015. Well, this shouldn't be surprising as you'll probably never find another monohull sailboat in its class that offers more comfort, more space, more luxury, and easier handling.

You can transform the boat's 3 cabins into 4 cabins by transforming the huge forward cabin into two smaller cabins in a few simple steps. In the bow, you'll find a large and luxurious master cabin that can be easily divided using an innovative Flexi-bulkhead.

Its sporty design on the exterior, lightweight composite steering wheels, and a flexible selection of wood tones makes it look so good while offering the best dimensions for both short and long trips. In essence, the Bavaria Cruise 46 is an elegant monohull sailboat that redefines modern sailboats with its clever and innovative design.

3. Hallberg-Rassy 48 Mk II

Following in the footsteps of the original Hallberg-Rassy 48 Mk that was launched a decade ago, the Mk II was launched in 2014 as an updated version thanks to its modern profile, incredible hull portlights, and larger and frameless windows. This Swedish monohull sailboat is solidly built, gorgeously finished, and is famous around the world and among sailors for its kind and smooth behavior at sea.

Its center cockpit is a true definition of what comfort should entail at sea. This is a monohull sailboat that will provide you with steady sailing both upwind and downwind. It can effortlessly cover 200 miles a day and doesn't require you to be a pro sailor to be able to handle it. If anything, it offers smooth sailing and can be perfectly handled by a casual sailing couple .

In terms of additional features, this monohull comes with a large chart table, lots of stowage and space, a secure linear galley, as well as extra machinery and gear that would be of great help when out on the water. This is a well-thought-out monohull sailboat and is perhaps the best Hallberg-Rassy ever built. This boat guarantees reliability, top-notch quality, and superb resale value.

4. Catalina 545

As one of the largest monohull sailboats in the game, the Catalina 545 stands out in the way it's engineered and designed to make it a truly excellent monohull sailboat. If you're an ardent Catalina fan, you'll notice that the 545 has some of the most eyebrow-raising features in bluewater cruising.

For example, the fiberglass collar is designed all-round the top of the hull and shaped like a construction beam. This is to give the hull a more enhanced rigidity while providing a sturdy base for the deck. It's also designed with solid stanchions and cleats, as well as strong sheer rails.

This superb monohull sailboat is constructed with a set of scuppers that play a crucial role in draining near the waterline so that you can perfectly eliminate any development of streaks or strains on the top side of the boat. As far as the bow is concerned, the sprit brings to the table an essential but unique anchor roller, a self-tacking jib, and a light displacement that makes the boat quick even in light or moderate wind. In essence, this monohull sailboat is designed with simple but reliable systems that are easily accessible. Better still, it remains one of the biggest monohull sailboats around.

5. Discovery 55

Having been launched two decades ago in 2000, the Discovery 55 has unquestionably stood the test of time and remains one of the most preferred monohull sailboats for families and couples around the world. This is a well-balanced and elegantly designed sailboat that brings to the sailing world immense practicality, comfortable seating, a deep and secure cockpit, dedicated stowage, and a self- tacking jib among many other things.

If you've been on a sailboat and bruised or stubbed your toes, you simply appreciate hos the superb monohull sailboat is designed to keep you safe and secure at all times. From the grab rails and handholds to deep sinks in the galley, the Discovery 55 is designed with plenty of nifty details and the inclusion of many practical ideas.

This sailboat will probably never disappoint you. It is well-mannered, comfortable to live on for days if not months, and a true definition of modern and luxurious.

6. Contest 50CS

If you want a serious monohull boat that can help you extend your sailing ground with ease and perhaps without even realizing it, the Contest 50CS is the way to go. For close to two decades, this Dutch-made monohull sailboat has been a consistent performer even with its dry weight of 17.5 tons.

This monohull is designed with impeccable modern underwater sections and a completely balanced rudder. Although the in-mast furling may affect the boat's performance, this boat can still perform incredibly well without it.

The fact that this boat is designed with a mainsheet traveler and electric winches that can be easily accessed from the helm makes it an ideal boat for a small crew or if you're planning to sail shorthanded. The genoa is easy to tack and two people can easily gybe downwind under spinnaker.

In addition to having exceptional touches on the interior, you might be surprised to learn that the joinery finish of this boat is arguably among the best in the boating industry. This is a monohull sailboat that's easy to handle, well-built, and has weathered the test of time to still mix it nicely with the big boys of recent years. Well, the Contest 50CS might not be among the cheapest monohull sailboats around but its demand is still soaring even today.

7. Bénéteau Oceanis 45

Named yacht of the year in 2012, the Bénéteau Oceanis 45 remains one of the most popular monohull sailboats in the world and for a good reason. This is a sailboat that redefines the important themes that made the Oceanis 50 so popular in a much better way.

One of the most noticeable features of this boat is that the mainsheet is designed in such a way that it doesn't obstruct the cockpit as you tack or jibe. This just a start; the cockpit is nicely designed and will serve you just right during your sailing endeavors. This monohull sailboat comes with three or four cabins, two bathrooms, and has a larger cockpit than other boats in its class.

This is a boat that keeps up with the Bénéteau tradition of being ahead of the game in terms of innovation, attention to detail, and offering top-notch performance. Whether you're looking to live aboard or sail to the remotest of places, this gorgeous monohull sailboat has everything you need in place.

8. Jeanneau Sun Odyssey 36i

Another French monohull sailboat that makes it to this list, the Odyssey 36i is a great monohull sailboat that is acknowledged for having some excellent assets in terms of sailing as it is faster and more agile than most sailboats. This is, without a doubt, an elegant monohull sailboat that brings to the sailing world an overall melodious package in terms of its modern design, power, and capability when sailing.

Even though its hull is of modest size, this monohull sailboat offers great value as it is easy to sail, easy to moor, and dock. Its magnificent electronics, folding prop, and electric anchor winch seem to make everything so easy that you do not even need a crew to sail this boat. The hull is lively and offers good acceleration. Imagine a monohull that can clock around 6.4 knots when sailing upwind.

To be honest, the interior of this boat is still very traditional but the exterior looks quite modern. The exterior is designed like an avant-garde sailboat and looks appealing from just about every angle. In terms of performance, this boat is designed with a deeper keel, spinnaker gear, taller rig, and a much better standing and running rigging.

On the interior, the most noticeable feature is the removable dining table that can be easily removed to accommodate extra bodies. Apart from that, there is nothing complex about the cockpit and deck layout. The double-roller bow fitting is nice and it comes with an optional electric windlass. In essence, this monohull sailboat is designed with lots of features. It is good-looking and reasonably priced.

9. Gunfleet 43

For many sailors who have the dream of spending most of their time sailing to exotic places, the prospects of downsizing and living most of your essentials at home can be daunting. In other words, it's almost impossible to pack all your life in a 40 feet vessel if you've lived your entire life in a 2,000 feet house. While you can't bring things like your hot bathtub to the ocean, the Gunfleet gives you the chance of bringing most of your essential onboard thanks to its immense spaciousness.

This British-built monohull sailboat is modern, sleek, but kind of feels like a classic sailboat. It comes with an efficient hull that's laid up by hand to enhance attention to detail. The reverse transom brings to the fore a three-step ladder leading to the deck and a small swim platform. It's also designed with a low coach roof and a windshield that seems to taper towards the aft of the cockpit.

Its impeccable low profile gives it a contemporary look but the center-cockpit design is the most attractive part of its design. The aft deck section is expansive and comes with excellent twin zones for sunbathing. They're divided by a skylight and a hatch that lead to the master stateroom that's located below. Its two cabins and two heads are essential if you're planning for long passages. The interior is posh and offers ample natural light.

As far as performance and acceleration are concerned, this monohull sailboat holds well. It accelerates nicely even when out of tacks since the helm is responsive no matter the point of sail. This is an outstanding monohull sailboat that has a solid feel and will most certainly boost your confidence if you're planning to go for long passages even in snobbish conditions.

10. Island Packet 35

Designed to offer top-notch performance, stability, and comfort, the Island Packet 35 is widely known for its spaciousness, modern interior, U-shaped galley, and a vast cockpit that certainly compares to most modern 40 feet sailboats while still holding to the classic lines.

This incredible monohull sailboat is designed with a short spoon, generous spring to the sheer, and a chopped off transom. It is perfectly designed bowsprit elongates the sheerline, which essentially makes the boat appear longer, lower, and much better than it is. As far as the keel is concerned, this is a full keel that's not heavy but very moderate.

The interior of this boat will probably make you think that you're looking at a 40-footer sailboat. It's so spacious that you can use it for your liveaboard sailing escapades. It also offers notable improvements in performance and certainly surpasses some of the company's earlier models. In ideal conditions, very few boats will match the Island Packet 35 in terms of performance. This is a very stable and comfortable monohull sailboat that doesn't hold back as far as performance is concerned.

11. Bowman 40

Thanks to its medium-to-heavy displacement structure, the Bowman 40 is designed to sail across open seas with ease. A modern classic, this monohull sailboat looks pretty much traditional thanks to its overhanging bow, deep-bilged, and narrow shoulders. This makes it very powerful on the waters and offers a lot easier motion during long passages.

Better still, this sailboat is perfectly stable and enjoyable since you won't be thrown about even in strong waves. It's designed with handholds within reach both above and below the deck, as well as no sharp edges to ensure that you don't injure yourself. This is enabled by the balanced hull and carefully integrated sails, as well as ample ballast that's neither heavy nor lightweight. In short, this is a solidly built monohull sailboat that will serve you diligently even when you are confronted with stormy conditions.

Honestly speaking, the Bowman 40 isn't a racing cruiser but neither is it a slouch. It has the ability to sail through the heaviest of oceans and might arrive at your destination just at the same time as other lightweight sailboats. This is, without a doubt, a sailboat that's designed to take you offshore in all weather and sea conditions.

12. Bavaria Cruiser 51

Even though it is one of the largest monohull sailboats, you'll probably never notice this once you start sailing. Well, this is because it handles unbelievably so well and can easily and comfortably accommodate up to ten crew members thanks to its three cabins. To offer optimum luxury, this boat can be customized to have five cabins, which is clear evidence that it can meet various needs.

This boat isn't just about being spacious. Instead, it's designed with all functionalities to enable you to enjoy your sailing adventures. Whether you take a look at its exterior, interior, deck, or cockpit, you'll realize that every part of this gorgeous monohull sailboat oozes class. While the most striking of this vessel's interior is its enormous space, it's also designed elegantly and beautiful to ensure that you enjoy your sailing adventures.

In terms of its hull, you're getting a very agile boat that you can easily control even when the winds are extremely strong. In essence, this is a monohull sailboat that's well and generously proportioned in all aspects. It's modern, sleek, and will turn head whether at the dock or deep at sea.

13. Wauquiez Centurion 57

Thanks to its exciting Mediterranean-style design and functionality, the Centurion 57 is a serious monohull sailboat that feels robust, solid, and truly marks the reincarnation of the legendary Centurion generation of luxury monohull sailboats. Designed as a racing sailboat, the Centurion 57 is thoroughbred, powerful, and impeccably maneuverable but that doesn't mean that you have to use it as a racing cruiser.

Instead, it's comfortable, luxurious, and elegant and brings to the fore everything that French boat makers are known for: class, beauty, and reliability. Its hull is unquestionably one of the most powerful and versatile. It's designed to withstand the harshest of sailing conditions .

It has a very spacious and large cockpit that's designed to afford you maximum versatility while out there. This means that you'll get lots of free space to efficiently maneuver the boat in the tightest situations and also to make things a lot easier if you're sailing shorthanded. From the electric winches to the helm position, you can easily access the transoms.

This is a monohull sailboat that guarantees calm, luxury, and comfort without compromising on performance and speed. It oozes modernity, solidity, and immense attention to details.

14. Rustler 42

If you've been looking for a monohull sailboat that combines serious performance attributes to other crucial blue water cruising elements, look no further than the Rustler 42. This is a gorgeous, fast, and reliable monohull sailboat that remains the benchmark of all monohull sailboats of its size. It not only offers directional stability but can also carry immense loads and is solid enough even for long passages.

This is a classing looking monohull sailboat that perfectly combines traditional style with modernity and innovativeness. It is not only elegant but also very stable and should be an ideal choice if you're looking for the best liveaboard monohulls.

Its spacious cabin is big enough to offer standing headroom and, of course, plenty of storage within the lockers. The hull is hand-laid using glass fiber reinforced polyester to ensure that it's solid, reliable, and durable.

In Conclusion

There you have it; the above-described vessels are the best monohull sailboats today. They are designed to enhance your sailing experience and ensure that you always enjoy your time out there on the water. Whichever boat you choose, it's essential to ensure that it's in good condition, well-maintained, and in perfect shape for your adventures.

Until next time, stay safe and happy sailing!

I've personally had thousands of questions about sailing and sailboats over the years. As I learn and experience sailing, and the community, I share the answers that work and make sense to me, here on Life of Sailing.

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racing sailboat ClubSwan 36

Overall length : 11 m Width : 3.6 m Draft : 2.75 m

The fortune of Nautor’s Swan was born with a 36 footer, one of the first few yachts built in fiber-glass. When the Swan 36 arrived on the scene a new datum was set. With her combination of fast lines, incorporating the modern separated ...

racing sailboat AC40

Overall length : 11.8 m Width : 3.38 m Draft : 3.5 m

Presenting the AC40, a scaled AC75 foiling day-racer designed by Emirates Team New Zealand and built by McConaghy. A one-design class that brings America's Cup foiling performance to a competitive ...

catamaran SL 33

Overall length : 12.6 m

Main advantages of the SL 33 one design! Excellently well tested, we are foiling for nearly 2 years together with ETNZ and Luna Rossa Our foils come directly out of the AC Lowest possible weigth, built out ot prepregs ...

catamaran TORO 34R

Overall length : 10.4 m

Our original TORO34 flirts easily with 25kts and more off the wind… How could we make the Toro to blow 30kts? Design Catamaran is in the final stages of releasing the TORO34R, equipped with foils, a 6.1m (20’) beam and a 15.9m (52’) mast. ...

foiling sailboat

Overall length : 4.2 m Width : 2.4 m Sail area : 11 m²

AWARD WINNING BOAT THAT’S TWICE THE FUN Airborne foiling or sailing with a daggerboard. Foiling is a sport that is here to stay. Foiling has been around for years but until now it ...

trimaran F-22

Overall length : 7 m

The F-22 is a new design that has been developed in New Zealand by Farrier Marine (NZ) Ltd. The production F-22 is now available and is being built in the United States. The F-22 was initially available in plan form for those who wished ...

fast cruising sailboat Code 1

Overall length : 12 m Width : 13'00" Draft : 4'01", 9'09"

This magnificent Vintage style, 40-foot yacht, cruising-racing boat built entirely in carbon, with the help of the best French specialists is testament to Black Pepper’s® commitment to “Luxury” and “French Art de vivre”. A purely exceptional ...

catamaran Befoil 16 CARBON

Overall length : 5 m

The Befoil 16 CARBON is a foiling catamaran that offering speed and accessibility. Designed and assembled in France, our high-tech carbon sailboat combines lightweight, aesthetics, stability and performance. We ...

foiling sailboat F101

Overall length : 5.4 m Width : 2.55 m Sail area : 9 m²

Foiling World started gathering experience about dinghy foiling 10 years ago when Alan started teaching foiling on International Moths. It soon became apparent that Moths were not the ...

Overall length : 8.1 m

Technical characteristics Hull length with rudders Beam Mast height Draught Carbon epoxy S-Foils Weight of craft Architect / Design plans Builder Hull Graphics Project 8.10 m/26.6 ft. 4.30 m/14.10’ 13.70 m/44” 1.20 m/3.93’ 325 ...

racing sailboat Q30

Overall length : 9.15 m

The new Q30 is closely related to and a further development of the pre-series DSS boat Q28. The Q30 combines unparalleled performance with easier handling on the water, as well as during boat preparation and transportation. The Q30 is ...

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Foil Assist: small or large monohulls

Discussion in ' Sailboats ' started by Doug Lord , Dec 11, 2005 .

Doug Lord Guest

I'm thinking of this particularly in reference to a small boat in the Moth range or a bit larger but I imagine it could be used to one degree or another in large mono's as well. On a small boat I envision a boat designed to plane but that would use a shorter, longer chord, lower aspect daggerboard foil than normal with a hydrofoil on the bottom -same on the rudder. Both daggerboard and rudder foils would be retractable and the mainfoil would have an easily adjustable(with a knob+screw?) angle of incidence. The foils would be short to prevent a crash from too much altitude if the boat got going fast enough for 100% liftoff and to permit the foil to be retractable(foil needs to be on the bottom of the rudder or daggerboard for this to work). Area would be based,loosely, on the same foil loading as the Moth so they would have more or less half that area for the same weight or more than half for a heavier boat.Lots to learn- maybe the foils could lift 60% of the weight?(Foil lift would be apportioned at approx. 80% on main foil; 20% on rudder foil) There would be no altitude control system since the hull effectively does this when the foil is properly set up. ORMA 60 multies use "foil assist" with curved daggerboards that theoretically take around half the weight of the boat reducing the ama loading. I bet this would work and be a good way to break into full flying foiling and maybe be a blast in its own right. What do you think?

tspeer Senior Member

The Catri trimarn uses much the same principle. Foil assist, with the hull partially in the water for stability and trim. There's really not much drag you're going to reduce by shortening the board. Any effective extension to the span by a foil at the end costs more wetted area than physically extending the span would. As for whether lift on the foil would reduce the drag, a foil's optimum L/D occurs when the induced drag and profile drag is equal. Since the foil is wetted on both sides, it must reduce the wetted area of the hull by roughly four times the planform area of the foil to break even.

foil assist Thanks ,Tom. The shortening of the daggerboard/rudder was an idea for a foil trainer that would hopefully prevent crashes from too much altitude if the foils ,for one reason or another, developed too much lift.It's not necessary or desirable on most monohull applications of "foil assist". I looked at the foil performance(roughly) for a 785 pound SDB(Sliding Deck Ballast) boat I'm designing with 255 sq.ft.SA,a D/L of 60, SA/D=48 and a SCP/disp.=30%. For foils with a total area of 2.68 sq.ft. one side it looks like "break even" according to your definition, would be just under 10 mph with a 63412 foil at a Cl =.6 and at 12mph the reduction in wetted surface would be 7.27 times the foil area . Using a flap @ 20° and a higher AOA to get started "break even" could occur at 7mph. -- I didn't factor in the boat most likely starting to plane at around 8mph which will be interesting in combination with the foil assist system. Seems to me that the concept has potential at least on this type of boat.

Tim B Senior Member

If you're using foils, you might as well get the whole hull out of the water (unless it is utterly impractical). Advantageously the wave drag then drops to pretty near zero. I would suggest that the strut for the rear foil be fixed, and independant of the rudder. This should reduce excessive sideslip on the rear foil, and thus excessive drag. The biggest problem I foresee is control. the boat will not "fly itself" due simply to the setup needing to be different for different conditions. I think there may be an advantage (for a smal boat) in using a gyro and servo setup to control the angle of attack of the rear foil, leaving the forward foil fixed. If you don't use some form of control you'll likely end up with a new form of porpoising. Best of Luck, Tim B.

foil assist Tim, I see "foil assist" being used on monohulls that would otherwise plane and the "foil assist" just helps them to plane earlier and faster. The idea of partial lift eliminates the need for an altitude control system. The most successfull foilers that fly completely clear of the water use an altitude control system based on a "wand" surface sensor;. The wand is tied into a flap on the main foil not the rear foil(so far). On both the Rave multifoiler and the Moth monofoiler the rear foil flap control is seldom used. A guy built an I14 using manual control of flight altitude using the rear foil flap and nothing on the mainfoil-it worked but is not the ideal setup.It appears that for best control moving the flap on the mainfoil is the way to go(or maybe both simultaneously as Tom Speer has suggested). "Foil assist" is used on the Orma 60 trimarans to reduce the leeward ama displacement when the boat is flying the main hull. Foil assist can offer very much increased pitch stability as well as wetted surface reduction w/o the attendent problems of a full flying set up requiring altitude control.Since , in my monohull application, the boat will be planing wave drag is already overcome; "foil assist" just reduces the amount of load the hull surface has to support while planing.

So you are thinking of using foils to control what in power-boat terms is the running angle. I don't see how you can hope to do it in an anything like optimisable way without some form of control system. Also, there will still be wave-drag, because there's still something sticking through the water. Aircraft have been using a single tail-mouted elevator for many years (almost since conception) birds also use there tails for pitch control very sucessfully. You are into a question of aircraft stability and tail moment arms. Shorter moment arm, bigger elevator, but the faster it will respond. opposite for long moment arms. I have been flying model gliders for many years, and have found that given sufficient elevator, almost any glider (particularly true of slope-aerobatic models) is very responsive indeed. Sometimes there is a need to couple flap-mixing in with the elevator. This gives greater Clmax and is particularly useful around tight turns (as in slope pylon racing). I think this idea needs some investigation, which should not be difficult for a man of your capabilities. Tim B. I make no apology for non-marine terms used in this post, they can all be Googled if necessary.

foil assist Tim, there are numerous examples of the use of foil assist in multihulls: the Orma 60's, the Catri Tri and even on Steve Clarks "Patient Lady" C-class cat(banana foils + rudder t-foils)-all use(d) lifting foils w/o an altitude control system. I'm not familiar with any examples currently being used on monos-but there is no reason, that I know of , why it wouldn't work.You're 100% right: careful design and testing will be required for it to work well. That is not to say that even with the best designed applications there aren't problems: the Orma 60's have been known to exceed the design speed of the foils which causes the ama(with main hull flying) to come clear of the water. When it does the foil is likely to ventilate since it has all of a sudden gone from a fully submerged foil to a surface piercing foil and if it does ventilate a crash can result. If that doesn't ruin the day another problem may: many of the boats used the part of the ama still immersed as the main source of pitch stability; when the ama comes clear of the water the boat is unstable in pitch even on those boats equipped with t-foils on the main hull rudder(diagonal roll). On the monohull version the foils won't so much control the running angle as BE CONTROLLED by the running angle.They will ,however, tend to prevent divergence(pitchpole) from the nominal high speed running angle of the boat.Lot's going on but I believe a workable system is possible...

You might like to take up the question of fixed control surfaces with some free-flight aeromodellers. They are gods at this type of thing. One thing you notice though, is that there is a lot of cleverness in setting up said models, and they are only set up for one speed. That is not the most efficient solution for a boat, as I think you wil agree. Tim B.

Foils and Foil-assist for Sailing Super Yachts

Foil assist monohulls, foil assist 40fter, imoca 60 2016-2017 foil assist, 2015 imoca 60-foil assist.

Foil Assist for Windsurfer

Foil-Assist Keelboats

Foil assist for keelboats(not dss)-kuka light and others, design for dss-foil assist for keelboats, quant 28-foil assist keelboat / dss.

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IMAGES

Foiling Monohull Design
Foiling Monohulls
Kiwis reveal new full-foiling monohull America's Cup class design
It's happening: IMOCA 60' monohull with DSS foils : sailing
Foiling Monohulls
Foiling Monohull Design

COMMENTS

Monofoil: The pocket rocket that can foil in just 8 knots of breeze
Shortly after her re-launch at Easter, it was clear that the team had raised the game. "We can now foil upwind in just 8 knots of breeze," said Monnin. "And when the breeze builds to 12 ...
Foiling Monohulls
Welbourn's Quant 23 may not be the first fully foiling monohull—the foiling Moth and the Glide Free kit for Lasers predate it—but it is the first ballast keel-equipped monohull to foil. For this boat, Welbourn added winglets to the rudder and employed a pair of curved foils that partially retract upward into the hull.
Foiling Monohull Design
A One-Design Monohull With Foils. The best evidence that foiling monohulls truly are here to stay came just a month after the Vendée Globe start when Beneteau introduced its new Figaro 3 design, drawn by VPLP, at the Salon Nautique de Paris in December. This represented a huge commitment by one of the world's biggest boatbuilders.
BENETEAU
The Figaro BENETEAU 3 is the first production foiling one-design monohull ever created.It is a distillation of technology and innovation, the result of a collaboration between some of BENETEAU's best experts and the Van Peteghem Lauriot-Prévost (VPLP) office, the architects of the last two boats to win the Vendée Globe.. The prototype has been tested and the production of the boat has been ...
America's Cup
Despite admitting that the foiling AC75 monohull is a first for the sailing world, Emirates Team New Zealand design team leader, Dan Bernasconi, is confident that the concept will work in practice. The style of the foiling AC75 has never been seen before in sailing. Under the AC75 concept, the whole hull will lift clear of the water, supported by two or three of the foils.
Foil Assist Monohulls
Listen to the Sailing Booster video as they try to claim the same benefits for their ripoff foil. A monohull sailing vessel (102, 202, 402, and/or 502) having a lifting hydrofoil (104 and/or 204) having a stowed position and a deployed position in which the hydrofoil extends outward of a leeward side of the hull (138).
36th America's Cup: Different Design Approaches
The foil arms and foil control systems, and the D-section masts are supplied as one-design components. Every team designs its double-skinned mainsail and sailing systems, rudder wings and foil arm wings. Unlike nearly every monohull on the planet, the AC75 does not have a keel, centerboard or even a canard.
Radical 75ft flying monohull 'could be fastest America's Cup design
The new AC75 will be a fully flying monohull. Instead of a keel, it has two canting, ballasted T-foils to provide righting moment and the ability to self-right the boat in the event of a capsize ...
A Bénéteau with Foils
Followers of extreme sailing may know of Bénéteau's several-year program to develop a production monohull with foils. Well, let's qualify the term foils. The new 3 2 ' (9.75m) Figaro Bénéteau 3 does not rise out of the water like a Moth dinghy or multihulls on T-foil appendages installed on the centerline of the hull; instead, it has C-shaped port and starboard foils that increase ...
Foiling in the Monohull Stream >> Scuttlebutt Sailing News: Providing
With the monohull world increasingly embracing foils it seems timely to reflect on some of the lessons learnt over the past year and how 2017 and beyond look for the impact of DSS and for the ...
The Foiling AC75
Counteracting that heeling force on the AC75 is the boat's subsurface horizontal foil, adjustable wings that provide lift for takeoff and steady flight. On the opposite of the hull is the other ...
America's Cup foiling monohull raceboat design revealed
The Defender Emirates Team New Zealand and the Challenger of Record Luna Rossa have revealed the first details of the design for the AC75 foiling monohull that will race in the 36th America's Cup. Challengers heading to Auckland in 2021 will have to master the art of sailing with twin canting T-foils, which can be lifted out of the water on ...
The Amazing America's Cup AC75 Foiling Monohull Flying Boat
Patriot in flight, but out of control and starting to capsize, 16 Jan 2021. Source: America's Cup video screenshot. The AC75 operates with two completely different sets of boat dynamics: Waterborne while accelerating at maximum power to quickly reach foiling speed at 12 - 14 knots. Flying on the foils to reach a top speed that can exceed 50 ...
New Monohull Foilers 2018
It is 3.04 meters long, 1.45 meters wide, weighs 48 kg and supports up to 90 kg of helmsmen. Glass and epoxy construction with carbon reinforcements, epoxy glass and carbon brackets, t-bar adjustable bayonet turret, tilting central drift (classic) and two retractable L-shaped foils both for displacement and for launching.
The Foiling Dinghy
The Foiling Dinghy is an outstanding design of a foiing sail boat. Innovative but special. The video shows how if behaves in offshore wind conditions. Gusty ...
Foiling is Becoming a Sailing Style For All
Jul 22, 2024. Original: Nov 30, 2018. With the TF10, big-boat multihull foiling is now available to amateurs as well as pros. Any time I put a helmet on I become hyper-aware of every step I take. Precaution means there's an alternative to a happy ending. On one of my last rides of the 2018 summer season, the helmet was mandatory, as was the ...
Sailing hydrofoil
Hydrofoiling wingsail catamaran 17. A sailing hydrofoil, hydrofoil sailboat, or hydrosail is a sailboat with wing-like foils mounted under the hull.As the craft increases its speed the hydrofoils lift the hull up and out of the water, greatly reducing wetted area, resulting in decreased drag and increased speed. A sailing hydrofoil can achieve speeds exceeding double and in some cases triple ...
Hydrofoils for Sailboats
Italian Enrico Forlanini began experimenting with foils in 1898. In 1906, his 1-ton 60 hp foiler reached 42.5 mph. Alexander Graham Bell's HD-4 Hydrodrome flew on Bras d' Or Lake at 70 mph in 1919. And several sailing foiler patents began appearing in the 1950s. Notably, JG Baker's 26-foot monohull, Monitor, flew at 30-plus mph in 1955.
Foiling and Hydrofoiling: Everything you need to know
To date the America's Cup has not looked back with the competition taking place in smaller hydrofoiling AC50 catamarans in 2017 and the newly conceived monohull foilers, the AC75s, in 2021.
14 Best Monohull Sailboats
7. Bénéteau Oceanis 45. cmhogarth. Named yacht of the year in 2012, the Bénéteau Oceanis 45 remains one of the most popular monohull sailboats in the world and for a good reason. This is a sailboat that redefines the important themes that made the Oceanis 50 so popular in a much better way.
Foiling sailboat
racing sailboat ClubSwan 36. foiling with bowsprit carbon mast. Contact. Overall length: 11 m. Width: 3.6 m. Draft: 2.75 m. The fortune of Nautor's Swan was born with a 36 footer, one of the first few yachts built in fiber-glass. When the Swan 36 arrived on the scene a new datum was set. With her combination of fast lines, incorporating the ...
Manually hydrofoil on monohull powerboat
Ive been look at the concept of developing a monohull with a pair of foils- both at zero or extremely minimal angle of incidence while the aft foil either was on a pivot so as to make the angle of attack adjustable or so just a trailing edge to be adjustable. The concept, similar to a 1930s J3 Piper Cub with adjustable elevator angle of attack ...
Foil Assist: small or large monohulls
Foil Assist: small or large monohulls. Discussion in 'Sailboats' started by Doug Lord, Dec 11, 2005. ... loading as the Moth so they would have more or less half that area for the same weight or more than half for a heavier boat.Lots to learn- maybe the foils could lift 60% of the weight?(Foil lift would be apportioned at approx. 80% on main ...