Evolvement of foiling sailboats over the last 70 years

A clash of sensibilities, this forum is a very different "market" to one that suffers misrepresentation, appropriation and hyperbole I hope, like right of reply.
Just because politicians, corporations , etc in general can create a platform, build a brand and do it all the time, doesn't make it good reading or fact. The "sustainable future" line was particularly gag worthy, ala Artimus vid. But perhaps this is a cultural difference that I find difficulty in keeping down, comprehending.. Another part of "creating facts" is bombarding the listener with corrupting information, a real "sustainable future" can't allow that much oxygen . I learn heaps from forums but still like to verify information, I am surprised by the very small improvement in speed a foil creates in the possibly affordable real world as CT 249 quotes. I have designed and built stuff from information I have gleaned from forums and limited nautical experience , and it works well so far, and with some serious farting around I could work toward lift from foils, but then I like kites too, they're cheap {any sail] and provide lift and have possibilities . The verdict on foils for me is it is quite impractical and still very experimental even though I am prepared to travel light. The 3rd industrial revolution has armed many people with some handy tools . and foiling is evolving too, even if it's just for fun and remains a tiny proportion of craft.

 

QFP

 

No,Doug. The claim I addressed in post 87 was the claim you made in post 86. It can be read by anyone - I quoted it in the post above.
You did NOT say the foiling Opti was a high point "in the development of foiling sailboats" until post 88. Just to make sure you understand the sequence, post 88 came AFTER I had replied (in post 87) to your post 86.

The fact is that, as clearly shown in your post 86 that I copied above, you said of the foiling Opti that "In looking over the last 70 years, this is certainly one of the high points of experimental development", therefore rating it with the development of trapezes, foam sandwich, self draining, alloy spars, assys, mylar sails, light planing hulls, modern tris, modern cats, etc etc etc. A couple of little boats foiling cannot rate in importance with such developments.

I ask again, if foiling on a conventional dinghy was so much fun (and I thought it was fun but not amazing) why haven't you done it over the past 10 years or so? Going on about model tris is not the point. You make endless claims about how much fun sailing a full-size foiler is, but for years you have not done it.

If it's so much fun that other people should do it, why don't you do it?

 

Given your claim that it was a "high point of experimental development" it might have done a bit better than the first foiling Moth efforts of around 15 years ago.

The "carbon skipper" was Axel Rahm who was, at the time, probably in the top 10 Laser Radial sailors in the world. He was also 17 years old, whereas the maximum age for competing in an Opti is 15 and I think most sailors are around 12 to 14 years old. The experiment and subsequent lack of interest shows that a foiling Opti is possible, but not practical or desirable.

If the goal is to get young sailors foiling (say 13 to 15 year olds), it would be a lot more interesting to develop a foiling kit for the O'pen BIC, which has a much more suitable hull shape and rig (and likely could use a spin–off of Glide Free or second hand WASZP foils).

 

Have you seen this evolvement towards the cruising market, this full foiler-cruiser catamaran 53' project on progress :
https://www.sailingscuttlebutt.com/wp-content/uploads/2018/07/Eagle-Class-debut.pdf

 

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Foils are certainly not "impractical" in most applications nor are they "experimental" in most applications.
Be wary of "facts" that limit speed increases of full flying foilers to just 4%-see below. There probably wouldn't be an ongoing foiler revolution if speed increases were so small. But DSS equipped monohulls(designed from scratch as DSS) gain more than 4% in most conditions.
Many original "foiling" cats can only foil downwind but that is changing.
The Moth can foil upwind and downwind . The worlds first foiling keelboat the Quant 23 can foil upwind and downwind-upwind in 8 knots of wind -downwind in 5 knots of breeze.
The new Flying Phantom Ultimate Foiler Cat was projected to fly upwind in 8 knots of wind.

Here is a slightly dated article you might find interesting:
1) What will foiling do for you? – Yachting World https://www.yachtingworld.com/features/what-will-foiling-do-for-you-70244
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2) Also a simplistic look at the Moth and foiling by CNN:

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3) https://www.sailmagazine.com/boats/foiling-monohull-design
---2017 article predicts Beneteau Figaro 3 will reduce displacement by 900lb and increase speed by 15%
---Says new IMOCA foils are expected to boost performance margins by up to 10%
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4) Farr Introduces Infiniti 53 https://www.sailingworld.com/farr-introduces-infiniti-53
quote from article:
Britton Ward, vice president and senior naval architect at Farr Yacht Design, says that initial performance estimates show that fitting a DSS foil, particularly at reaching angles, can provide a performance increase on the order of 15 to 20 percent and at reduced heel angles.
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Keep in mind that DSS is "foil assist" and an equally well designed full foiling boat would be substantially faster than a foil assist boat.

 

Thanks for passing it on Dolfiman, below some links I've found from the article . . .

— Fast Forward Composites — Eagle Class 53 & 53 T — Autonomous Foiling System — Hybrid Wing —

 

Fact - the evidence that small cats gain only 4% speed advantage from full foiling comes from the SCHRS committee, formed under World Sailing.

Fact - The SCHRS committee has vastly greater technical knowledge about foiling cats than Doug does. Doug says he's done a bit of sailing in Hobies etc. In contrast, the head of SCHRS' technical committee is Will Sunnucks, holder of several national titles in fast cats like Tornadoes and line honours winner of the enormously popular Texel cat race.

Fact - the SCHRS committee has vastly greater experience in foiling cats. Doug, I believe, has never sailed a foiling cat and I'm not sure if he's ever sailed anything faster than a Hobie 16. Sunnucks, by contrast, is the prime mover behind the foiling Vampire cat. You can't compare his great practical experience in foiling cats with Doug's complete lack of such experience.

Fact - the SCHRS committee has vastly more information than Doug does. They analyse the results of 300 races per year in France, for example, to check that the rating system is equitable.

Fact - when the SCHRS committee initially rated full foilers, they assessed them as 7% faster. The major builder of foiling cats, NACRA, then gave the committee "emphatic feedback from Nacra that these penalties are too harsh. We still have very little hard data, but no foiler has yet come near to winning on handicap." The assessment of the foiler's extra speed was then dropped to 5% and again to 4%.

So when it comes to assessing the speed of small foiling cats, we can either believe a committee led by an expert cat champ who is an experienced sailor of foiling cats, using information from hundreds of boats in hundreds of races OR we can believe someone who did a little bit of cat sailing years ago, who has never won a significant cat race, has no particularly good access to performance data, and who has (I believe) not only not sailed a modern foiling cat but not even seen one. The logical choice is clear.

Fact - I pointed out in post 89 that "AC type foilers may well get much more than 4% advantage" so presenting their performance as proof that small foiling cats are much faster than 4% quicker than equivalent non-foilers is illogical.

 

Sounds like the builders got a good deal!

Checking the A-Cat ratings: Foilers = 0.978, Classic = 1.008.

That's only about 3% difference. (Seems awfully small to me!)

Any A-Cat sailors out there who would like to give their opinions?

 

You're dead right, Trip - we've got to verify the information we get on forums - and sadly these days the sailing media is full of people who don't do much research and write a lot of hype about boats they rarely, if ever, sail and basically never own.

 

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Here's a link to the Eagle thread in "Multihulls": Eagle Class 53 Catamaran Foiler https://www.boatdesign.net/threads/eagle-class-53-catamaran-foiler.60758/

 

Looking at the performance of USA 17 in the 2010 AC 33 (thanks to Tom Speer for awakening me to its performance), it can be seen that foiling doesn't help multihull boats anywhere near as much as monos, likely because multis are much more efficient to start with.

USA 17 achieved an upwind VMG of 1.5 times windspeed, and 3.5 times downwind. Without lifting foils. It would be very interesting to see it line up with an AC50 or F50, though at more than twice the length it wouldn't look like an even match.

However, once super–cavitating foils are developed, it will be onward to infinity and beyond. But right now they're a bit like nuclear fusion and quantum computers: the theory is well understood, but building a viable product is something of a challenge.

 

Interesting.

It would also be interesting to get more information on monohull foilers of different types. The Moth could perhaps be a very special case, because it was already very light, with a very low-drag hull, a large but very low-drag rig, and lots of beam. Once you get a boat of more normal proportions, you probably need a higher-drag rig and bigger foils to get going, which is going to hurt your performance. It's hard to find information on Quant 23 races, for example, but sometimes they seem to get beaten by some very conventional boats. The 12 Foot Skiff versus foiling R Class match-up that

I'm not an A Class sailor, but at the Queensland titles the world Classic champ Andrew Landenberger finished 5th out of 31 entries (27 actual starters) in a mixed fleet of foilers and Classics, despite 15-20 knots breezes that favoured the foilers. That put him one place behind the sailor who then finished 17th out of 69 entries in the foiling worlds, and ahead of the foilers that ran 21 and 27. Landy is an Olympic silver medallist and was 4th in the A Class worlds on foilers a few years back. He beat another Olympic medallist at the 2018 worlds so the top Classics are certainly extremely well sailed.

The second Classic at that state titles finished 8th of 27 boats that actually started. It was behind the foilers that ran 21 and 27 at the worlds and ahead the foiler that was 36th at the worlds and another foiler that averaged 27th when it finished, but got a bunch of DNSs. The Classic was 12th at the Classic worlds. So at top level, perhaps foilers are

Landy says that the Z and C foilers are also slower in very light winds than the old straight-centreboard boats, which would also obviously affect the ratings.

If I recall correctly, Andy reckons that the typical sailor often loses a lot of VMG trying to get up on the foils (although the typical A sailor is pretty damn good) which is part of the reason the spread between Gashby, Stalky etc and the rest of the fleet is so big. Given the enormous spread in the fleet, it must be hard to evaluate their performance in the hands of mortals. If I recall correctly, at the A or Moth nationals the leaders were sometimes rounding the bottom mark when the boats around 11th got to the first mark- and the guys in 11th are on top gear and sailing well. Perhaps there's a feedback loop caused by the fact that the foiler's drag is dominated by induced drag that reduces as speeds increase, whereas conventional boats are dominated by hull drag that increases?

 

No, I didn't say that Doug, I said for my purposes. I'm not into them like you are, I'll have a look at the threads you list over the weekend, if I get a chance . I already have some significant work to do building new floats from 3 donor sets of hulls, I don't think it's worth working toward foils for my boat , but I'll leave the cassettes in place. A small fast coastal cruising tri. I accuse you of wearing rose coloured glasses.and I'd prefer you edited better when you borrow/ readvertise marketing material. It affects your credibility.

 

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Could you be more specific and explain exactly what you're referring to?