AC 36 Foiling Monohulls

There isn't a single current foiler that I'd be keen to buy for a number of reasons (even if someone gave me a £25,000 voucher that I had to buy boat stuff with), so I think it's a mistake to count low sales as a reliable indicator of how things will be in the future. Evolution of foil designs has not settled down sufficiently, so the costs are high and no one has yet found the best compromise between performance, ease of control, safety, etc. Development classes aren't attractive for ordinary sailors, and the one designs clearly aren't in the right place yet. For most people, foilers are still just expensive, dangerous toys. New materials and construction methods will bring the cost of foils down once they've settled on the right designs and can focus on mass production, but I think there are better foil layouts and shapes waiting to be explored, better places to attach them than passing them through the middle of hulls, and I don't think many people want to end up racing at speeds of 30mph and risking serious injury every weekend. Gentler foilers which fly early and have a lower top speed would have much greater appeal, but they also need to be more stable so that you can afford to relax. I'm actually more interested in the idea of foiling in relation to cruising than for racing because it would provide the opportunity to cover a much greater distance within a weather window, and make it easier to handle strong currents without needing to motor. The kind of foiler I want to buy is simply not available yet, but I've seen enough of foiling systems to believe that it is possible to design something substantially better than anything on the market today, and that there are still some big advances there to be made (in terms of making foilers more civilised). Foiling is certainly not the future of sailing, but it will be a bigger and bigger part of the future of sailing as time goes on and new foilers home in on what most people want them to be. I don't think the new AC boats will do anything useful to help though - I'd have liked to see them switch to passive foils, because then they'd have started to explore new ideas that might relate to the ideal foilers for the masses.

 

In many ways I agree with you David except the "gentler" easy to sail foiler concept has been developed by Hugh Welbourn. The Quant 23(and now the Quant 17) is a boat specifically designed to be comfortable, easy to fly and designed to fly in very light air with top end speed not a priority.
And I believe that Hughs foil system would work very well on an AC boat where the emphasis would be on top end speed. It offers advantages for a monofoiler not even approached by the current TNZ renders.

Note crew positions below:

picture from Michi, builder of the boats--

 

Interesting. I must admit, given issues such as "wing loading" I find it hard to see how foiling will ever work well at normal cruising speeds, nor what new materials are on the horizon and how will they deal with the issues. How will a normal cruising foiler deal with day to day issues like anti-fouling, cruising style sails with their higher drag, and the vastly higher drag of cruising boats in general?

In that small percentage of places where overcoming foul tides is an issue, how will people handle the problem of foils hitting the bottom and the boats drying out without excessive cost and hassle?

If you want to go faster when cruising, why not go multi? Doesn't the fact that most people prefer slower boats for cruising indicate that few people would be interested in a cruising foiler?

It's interesting to work out the attraction in foiling. For many people it's the speed, but speed certainly isn't very important in itself - most Mothies could perhaps go faster on an A Class cat or Formula Windsurfer. The thrill of "flying" is rather similar - people have been sailing a metre or more about the water while supported by the lift of the boat for decades - it's just that they did it on a cat, or more rarely on a wing. Most people who sail don't care about "flying"; if altitude = excitement then boards are the answer. The thrill of something new and hyped is a factor, but it's a passing one. The joy of efficiency and sensitivity is perhaps at the bottom of it all, which is sensible. How will that translate to a cruiser?

Of course there IS a thrill in foiling and many of the boats are great, but if foilers are toned down for cruising will that thrill survive enough to make a foiler the logical choice for a significant number of people?

The Quant 23 isn't really a model for a popular class - only 10 have been built. They have stopped building "on spec" and are now only building on order. Compare that to the popularity of the J/70 for example - two boats per week for five years despite having several close competitors. That means that 13 production-line Quants of all types have been built in more than five years.

 

We discuss whether foils development influences the development of sailing. He certainly has. But does it affect the return of sailing ships. Probably not. However, the development of reefing sails would certainly have an impact on this.

 

I wasn't thinking about cruisers, but dinghies specifically designed for both class racing and cruising so as to provide maximum value for money. There are lots of people making trips in kayaks these days which few dinghy sailors dare to attempt, and a large part of the reason for that is that existing dinghy designs fail to provide them with what they need. I want a small, lightweight dinghy which I can manage alone (but which should also be able to accommodate two adults or an adult and two children) designed with cruising in mind so that you don't have do such things as carry additional planks of wood to create a platform to sleep on - a good design shouldn't need such cobbled-together solutions to fundamental problems that should have been addressed at the design stage. (It should also be designed with racing in mind though - it should initially aim to be fast, but then make some compromises in order to make cruising more practical.) The small size of a light boat of this kind invariably leads to it being relatively slow, but being able to get the boat out of the water easily on rocky islands is a high priority, so minimising weight matters. Clearly a cat might provide a better solution than a mono, but there's no reason why a small mono shouldn't also be designed to be a better cruiser than existing designs, and once up on foils, it could be as fast as an equivalent cat. The advantage of foiling when cruising applies to both cats and monos - you can more than get back the speed you've lost by going for a small boat if you can get it to fly. It should also increase your range under motor if you have enough grunt to get up on the foils, and if you're having to deal with a strong current in the Bristol Channel or Pentland Firth, this matters. Foiling would make a substantial difference to the practicality of such boats. Suppose you want to nip out to Rockall from St Kilda and back - it's 170 miles doubled (and you can't land there). Why should you have to buy/hire a cruiser for this when a well-designed dinghy could be capable of making the trip safely, and if you prefer sailing dinghies? I don't like bigger boats where you can't just reach over the side and touch the water as you sail along. I love dinghies, and I prefer them small. If you get the right weather to do that trip at speeds between 15 and 20mph, you could complete it in 24 hours. In displacement mode, it might take three days, and then you're going to have to sleep in a shipping lane. I'm not planning to make such a trip, but I wouldn't want to rule it out if I had a boat with that capability because the big appeal is adventure, and the smaller the boat, the bigger the adventure. (I certainly won't put myself in a kayak in waters with orcas though - someone's going to get nibbled before long.)

"If you want to go faster when cruising, why not go multi? Doesn't the fact that most people prefer slower boats for cruising indicate that few people would be interested in a cruising foiler?"

If I want to race my small dinghy without hydrofoils on a small loch (where slower designs make that loch feel bigger) and then take that same boat to the west coast and head out to remote islands, I need that boat to be versatile. If a weather window allows me to foil out to North Rona & Sula Skeir and back but might not last long enough to do the trip in displacement mode before the weather turns, I want to fit the hydrofoils. Why should I buy a second boat for this? Why should I spend a fortune keeping a cruiser in a marina and poison the sea with anti-fouling paint if I can make the trip in a small boat of a kind that I prefer sailing (and which allows me to get closer to wildlife)?

"Of course there IS a thrill in foiling and many of the boats are great, but if foilers are toned down for cruising will that thrill survive enough to make a foiler the logical choice for a significant number of people?"

For me, the appeal of foiling has nothing to do with thrill - you can get plenty of that in a planing Mirror. High speed with minimal disruption to the water is more like making a bog-ordinary trip in a car (with the main excitement being that of feeling like a god every time you overtake a cyclist). What matters to me is utility - foiling can solve some problems and extend the range of trips a boat can make. The handling needs to be made easier though so that it's less of a balancing act - you don't want to have to concentrate so hard all the time, and some foiling systems are more stable than others. I think there's a lot of room to improve this once the focus moves away from out-and-out speed. Of course, even if the AC boats were going in a "better" direction with passive foils (better from my point of view, but not necessarily for others), they'd be focussed on maximum speed rather than creating a more forgiving boat, but they'd still be doing a component of the latter, and some of their work might have helped drive things in useful directions for more ordinary foiling boats aimed at the masses.

On the materials point, I recently read an article about 3D printing with aluminium where they were producing objects two to three times stronger than could be produced through conventional methods. That kind of research is only just beginning and there are lots of metals and alloys to be experimented with, so it isn't impossible that something will come out of this at some point that has a relevance to foils. There's also the whole business of how making foils out of CF can be automated and the costs slashed - we can't make much progress with that until foil designs settle down, and most of the cost is down to the high amount of man-hours involved in construction of things that will some day be done entirely by machines.

 

That's a big ask, David. You're calling for a boat that has a higher average speed over 24 hours than a Moth or A Class, while not accepting at least some of the obvious compromises AND apparently demanding a level of sailing ease that no small sailing craft has ever obtained in such conditions.

As an analogy, it's a bit like saying in 1970 "I want a cruising dinghy that will go faster than an A Class cat or International Canoe does on flat water, but do it for many miles offshore while being as easy to sail and move around as a Mirror, with superior safety and accomodation than a Wayfarer, and it will be possible soon because carbon fibre has been developed." Even decades later, there's still no such craft.

As another analogy, it's a bit like saying in 1970 "I want a campervan that will go faster than a contemporary F1 car does around a racetrack, BUT do it over rough roads while being easy to drive and without a berth that uses a cobbled-together solution like a poptop or a convertible dinette, and it should be possible because carbon fibre has been developed". Even today there is nothing like that on the horizon, and a quick Google indicates that campervans still use "cobbled together" sleepoing solutions because physics don't change.

Arguably there are too many insuperable issues, such as the contradiction between the need for a low drag rig for foiling speeds, and a cruiser's high-lift reefable rig. It's a bit like the fact that theoretically, it is easy to give a cruising dinghy practically all the righting moment you ever need - all you need is to give it skiff-style wings that are each 14ft wide and the crew can sit on the nets, comfortably out of the spray. In reality, of course, such wing width is completely impractical. The fluctuations in the element mean that there are major limits on what could theoretically be done.

May one ask how much experience you have averaging such speeds over the ocean and sailing small high performance craft and foilers?

A sailor/sea kayaker I know reckons the sea kayakers just have a different attitude to danger, not superior equipment. After all, dinghies and windsurfers Similarly, have done just about every major ocean trip a kayaker has done, I think, so they can certainly do it.

It's interesting that the sailing boom arose from designs that did not attempt to cater for anything as extreme as your wish list. There had been some amazing long-distance ocean voyages in small craft in the 1800s, but they caused little more than a collective gasp and indifference. The sailing boom arose from craft designed for much smaller horizons; the sort of thing that people could see themselves doing on a long weekend or short holiday, with minimal risk. The Dye's cruises were inspirational but they occurred well after the dinghy boom was in full swing.

The connection with the AC75 is that even in an aspect like small-craft cruising, popularity arises when people are presented with gear designed for something the typical sailor can aspire to do on a typical local weekend or holiday, not with more extreme sailing in mind.

 

It could certainly be difficult to find the right weather conditions to make such a trip, but I wouldn't call it impossible. I was simply trying to indicate the upper end of what might on rare occasions be viable. At 15mph you would cover 360 miles in 24 hours, and that isn't a particularly ambitious speed if the weather's ideal. Nor would sea conditions necessarily be greatly testing - I've been out as far as St Kilda and near the Flannan Isles in conditions with a reasonably smooth sea and a constant breeze day and night that would comfortably keep a good foiler flying at and above the required speed.

"As an analogy, it's a bit like saying in 1970 "I want a cruising dinghy that will go faster than an A Class cat or International Canoe does on flat water, but do it for many miles offshore while being as easy to sail and move around as a Mirror, with superior safety and accomodation than a Wayfarer, and it will be possible soon because carbon fibre has been developed." Even decades later, there's still no such craft."

When I talk about accommodation, I don't mean sticking a ruddy great hotel on a boat - I'm talking about things as simple as not blocking potential sleeping space with a fixed thwart, or shaping buoyancy tanks in such a way as to provide a few extra inches of shoulder room between them and the CB case (or putting all the buoyancy into the floor to remove the need for side tanks.) Go and look at a typical small dinghy and ask yourself if it's been designed to enable someone to sleep in it, then ask yourself how much you'd need to change to make that possible and how much that would slow it down. The answers are likely to be: not possible, very little modification, and no measurable loss of speed - they were not designed for sleeping in, but they easily could have been.

The CF issues relate more to cost reduction rather than to minor reductions in weight and robustness (which would be helpful rather than revolutionary).

"Arguably there are too many insuperable issues, such as the contradiction between the need for a low drag rig for foiling speeds, and a cruiser's high-lift reefable rig. ... "

What I'm talking about is a small boat initially designed for racing, then compromised as minimally as possible in order to provide better cruising (at close to race speed) capability. I'd still want to race the thing out on the ocean, but I don't want it to be as hard as riding a unicycle if I'm sailing all day. Small compromises can make a boat massively more comfortable without scrubbing off significant performance. The biggest acceptable compromise would be with the foiling system, allowing a bit more drag (if necessary) in return for greater stability while still achieving reasonably high speeds. It may well be possible to reduce drag and gain more stability over current systems though. I'm now looking at a six-foil solution where three or four foils are in the water at the same time (3 upwind, 4 down) and there are no moving parts beyond changing foil pitch and steering. I think it could beat current foilers round a course and provide grater pitch and roll stability.

"May one ask how much experience you have averaging such speeds over the ocean and sailing small high performance craft and foilers?"

Absolutely none. No one has any experience of sailing the kind of boat that I'm visualising either because their foil designs are driven by rules (such as insert from above) which restrict their ability to evolve in the direction I think they should be taking. With Z foils, for example, you have a considerable component of lift working against lift from the opposite foil to generate drag for no gain, and along with that comes increased roll because the boat depends on lift from the windward foil for overall flight altitude rather than just for setting the altitude of the windward hull. They are still a fair way short of optimal.

"It's interesting that the sailing boom arose from designs that did not attempt to cater for anything as extreme as your wish list."

Don't fixate on the extreme examples I used to illustrate things - those were indicating the more adventurous end of things. The main purpose for me is simply for island hopping in archipelagos such as Orkney, Shetland and the Western Isles of Scotland, plus the occasional more daring trip out to isolated islands further out if the weather allows it. There are many places where keeping the boat small and light is essential if you want to be able to land, and there's a major utility difference between a boat that can be carried by two people over rocks and one that can't.

"The connection with the AC75 is that even in an aspect like small-craft cruising, popularity arises when people are presented with gear designed for something the typical sailor can aspire to do on a typical local weekend or holiday, not with more extreme sailing in mind."

What I want to do with an ideal boat is not something I consider extreme - it is something that could become mainstream once boat designs cater for it, but current designs make it extreme because they simply haven't had the vision to get their boats right.

 

David, it's insulting and baseless to claim that the designers lack vision. Foiler designers include people who have shown the vision required to lead development in their field and launch new classes. Many of them have experience with small high performance craft, unlike you. They therefore know what is possible and what is not, unlike you. Why do you assume that they lack vision, instead of assuming that you lack knowledge?

It was obvious that you weren't talking about a hotel, which is why the reference was to a Wayfarer's "accommodation" which is not hotel-like. The issue is that doing things like putting all the buoyancy in the floor has significant effects on things like legroom and inversion. Putting in planks for a bed is not just a "cobbled together solution" to an issue that has been ignored, but a logical response to the factors - and a response shared by people such as campervan designers.

There are many current small craft that could do the passage you mentioned in ideal conditions. They don't. The problem is not lack of speed but the rarity of such conditions and the problem of what happens when they change. As noted, one could just as easily say that a Wayfarer or Mirror could do the Rockall run as quickly as your potential foiler if one just fitted it with 40ft wide wings and a skiff rig. By the same sort of theories you appear to be applying, it's a cheaper and simpler solution and just as practical. Anyone who has actually sailed wide wings knows the insoluble problems in reality, which shows the difference between theory and reality.

After many years of development, fully foiling sailboats are still more problematic in rough seas than their non-foiling versions. I used to sail what was possibly the first semi-foiling class and we found significant problems with that configuration offshore as early as the '80s. Foiling is fun but it isn't new nor has it ever been widely popular in any configuration and therefore the AC foilers are highly unlikely to be representative of anything but a small niche, and that is not helpful to the sport as a whole.

 

This is way off topic here, please start a separate thread.

 

I don't appreciate the way you're twisting a comment about lack of vision in relation to dinghies failing to make small design tweaks (which don't harm performance) to make sleeping in them practical into an assertion that I'm accusing foiler designers of lack of vision in designing foilers. That accusation is an illegal move.

"Putting in planks for a bed is not just a "cobbled together solution" to an issue that has been ignored, but a logical response to the factors - and a response shared by people such as campervan designers."

It's a lot of extra weight and highly inconvenient junk blocking up the boat while sailing, and it's wholly unnecessary in cases where a few changes in design could have avoided the problem if a bit more imagination had been applied.

And yes - this has gone off topic, so I'm certainly not going to spend any more time responding to off-target attacks. The important issue is whether there are still new foiling possibilities waiting to be explored and whether the AC boats are pushing in useful directions to find things that will filter on down into normal boats for normal people. I wouldn't be surprised if something does (for those who like to rely on power-hungry machinery), but I think there are better directions that could have been taken, and I've tried to explain why I believe that.

 

It's BS to think that any AC design is designed similarly to designs suited for general public, they never have been ... and never will be ... and the lifting leg reptile is no exception.

 

David, nothing I said was an "attack" in the way that the claims that designers "haven't had the vision to get their boats right" or fail to apply "a bit more imagination" were.

To try to bring it back directly on topic. The closest thing to the AC75 is probably the Quant 23. After a great deal of promotion and, one imagines, a great deal of investment they have built 9 or 10 and the regular production has stopped. The Quant also comes from a region that has been heavily involved in radical racing boats for decades, so there's probably less resistance to novelty (if any) than in other areas. And yet the boat is not attracting buyers or apparently having much real impact. Given that it's reasonable to surmise that the AC boat may not have a great impact.

In the past the AC boats have normally formed a tiny proportion of a large group of similar boats. Magic was a big version of the classic US centreboarder, Reliance was the big sister to hundreds of Half and One Raters, Ranger was the big sister to hundreds of S, R, Q class and Metre boats (to which they were linked by an agreement between the Brits and Americans), and the IACC class was designed to be much more like a sportsboat (and therefore a big version of a Melges 24 etc) than it ended up being.

The AC75 is now the third AC class in a row that does not form part of a larger group. It also looks as if the recent classes have not inspired a major growth among smaller but similar boats. For example, the committee that runs the major beach cat rating system has changed its rules about new designs because the market for them is "low". In the world's biggest beach cat race the foilers appear to have made up less than 3% of the fleet, and that's in an event that is used as a showroom and despite the Olympics including a foiling cat class. Analysis of national titles in the UK, US and Australia show no significant increase in cats since they entered the AC.

As another measure - there are 10,000 International class boats sold each year. After huge publicity, two ACs and one Olympics involving foiling cats, they make up just 95 of International class boats sold each year, or .0095 of the total*. Never in the history of sailing has so much indifference been paid by so many towards a type that has caused so much hype and been used for two of the sport's greatest prizes.

Given the fact that the foiling AC cats have failed to make any significant impact on what the typical sailor sails, there is little evidence that a foiling AC "keelboat" will have any significant impact on what the typical sailor sails.


PS - none of this is a slur on AC boats. Some of the classes I own and love are not very popular, and at least one of them arguably harmed its section of the sport by promoting the inaccessible elitist side. We have to separate the evidence about the effects of a class from our individual feelings about that class.


* Yes, there are non-International foiling cats - but if count them we also have to count non-International seahuggers, which include many classes that are very popular such as England's Solo, Australia's Sabre, the plastic Opti copies. Also note that the International Hobie and Bic classes, which are not foilers, don't report their class sales and therefore in reality the number of International class seahuggers that is sold is considerably higher.

 

So GT, you think Reliance was similar to Half and One Raters - did you check out proportional displacement? - there are light years (no pun) in difference. Because One Raters and Napier Patikis had no ballast and were 27 foot ultalights - whereas Reliance was massively heavy.

 

CT - what do you think will happen when AC returns to having non-foiling monohulls? Will hordes of people rush to sailing clubs with little tubs because they're so excited at the AC action that they never bother watching? No, they won't. The AC is about prestige and advertising of products unrelated to sailing - it's a display of wealth. You need to stop blaming it for sailing's woes and recognise that the real problem lies elsewhere.