Foiler vulnerability to trash in the water

[Doug Lord]

People that sail the boats have opted clearly to choose tight trunks and to minimize control linkage slop. That is why Moth people walk their boats out "capsized" to deep enough water to right the boat and start sailing with the foils fully inserted.

--
Bill

<awaiting the predictable onslaught from our resident expert>

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Whereas boats like the RS600FF, Rave and others have solved the problem(s) and can be launched like any other dinghy...

 

[bistros]

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Whereas boats like the RS600FF, Rave and others have solved the problem(s) and can be launched like any other dinghy...

For frig's sake, the Rave has been discontinued longer than George W. Bush. So has the Hobie Trifoiler. RS Sailing stopped selling the RS600FF, it is only sold by Full Force now. The FF is now available with carbon hull for only about +$1000, making all the prior RS600 conversions uncompetitive, as the carbon hull is better in all aspects according to the Full Force website. The Tomahawk foiled boat from Ovingtons never made it past infant mortality. Your aeroSKIFF seemed to have had a camera-killing magic field around it every time you said it foiled. It certainly isn't a foiler today.

Basically, Doug the Moth IS the only real production foiler out there today. It's numbers now dwarf all others by an order of magnitude. It's foiling ability - foiling gybes, foiling tacks, light wind takeoff, International racing circuit and ongoing development make it the de-facto standard.

Yes, Full Force has made a retractable T-foil in a low volume production boat available today. Add on the new rig and it isn't a class legal RS600 anymore, so a lot of the purchase justification is gone.

Stop bringing up irrelevant, failed and discontinued examples to support your arguments. It's like someone talking about how the Pontiac Firebird is the best sports car on the market when Pontiac doesn't exist anymore.

--
Bill

 

[Doug Lord]

For frig's sake, the Rave has been discontinued longer than George W. Bush. So has the Hobie Trifoiler. RS Sailing stopped selling the RS600FF, it is only sold by Full Force now. The FF is now available with carbon hull for only about +$1000, making all the prior RS600 conversions uncompetitive, as the carbon hull is better in all aspects according to the Full Force website. The Tomahawk foiled boat from Ovingtons never made it past infant mortality. Your aeroSKIFF seemed to have had a camera-killing magic field around it every time you said it foiled. It certainly isn't a foiler today.

Basically, Doug the Moth IS the only real production foiler out there today. It's numbers now dwarf all others by an order of magnitude. It's foiling ability - foiling gybes, foiling tacks, light wind takeoff, International racing circuit and ongoing development make it the de-facto standard.

Yes, Full Force has made a retractable T-foil in a low volume production boat available today. Add on the new rig and it isn't a class legal RS600 anymore, so a lot of the purchase justification is gone.

Stop bringing up irrelevant, failed and discontinued examples to support your arguments. It's like someone talking about how the Pontiac Firebird is the best sports car on the market when Pontiac doesn't exist anymore.

--
Bill

=====================
The RS600FF is in production with an industry standard retractable foil system and the class is growing with performance similar to a Moth. The Rave IS still being produced- last I heard- by a new company. But what is more important is that the Rave was produced with a retractable system that is first class , with two different sailing positions that still works as well as when the boats were first introduced! The new Osprey will use the same system. And you ignore the major implementation of retractable foils on boats like Hydroptere and Spitfire and many other boats.

 

[bistros]

=====================
The RS600FF is in production with an industry standard retractable foil system and the class is growing with performance similar to a Moth. The Rave IS still being produced- last I heard- by a new company. But what is more important is that the Rave was produced with a retractable system that is first class , with two different sailing positions that still works as well as when the boats were first introduced! The new Osprey will use the same system. And you ignore the major implementation of retractable foils on boats like Hydroptere and Spitfire and many other boats.

Given your wondrous Foilapedia collection of Internet posts and hearsay containing the word hydrofoil, could you provide numbers to support your position? How many Raves were produced under it's original ownership? How many have been (NOT expect to be) have been produced by the "new company"? How many Ospreys have been (NOT expect to be) produced? How many Hydroptere(s)? How many RS600FF (complete boats)? How many RS600FF foils kits? How many RS600FF Carbon? You get the idea.

My point is simple. Just because one or two boats of a type have been prototyped, the sample is not statistically significant. Measuring against a total of all produced foilers is the only realistic measure in a niche market this small. I personally would not bother with mega-dollar one-off records chasers, as they never were or will be intended to bring foiling any market volume. Can't say as I see anyone building their own Hydroptere any time soon. As well, in the case of the RS600FF what do you mean by "growing"? Is this an indication there are 15 already on the water (with the now deprecated uncompetitive glass hull) and there has been 2 carbon hulls sold? Or do you mean there are 200 on the water and orders for 300 more?

Counting "designs" isn't relevant - there may be 35 designs out there that have never made it to one hull or past the first hull. Creating a comprehensive list of all boats STILL IN PRODUCTION making it to 5 hulls may be a great place to start. Homebuilds don't count. My friend Sam Schneider's boat should not count (although it will probably end up better than most "production" efforts).

Statistics are slippery, and statisticians are slipperier. You have to analyze things VERY carefully and have access to all the raw data, as well as establishing a framework of relevance to be able to draw any conclusions.

--
Bill

 

[Chris Ostlind]

...Apart from yes stuff affects foils, it'd be nice to sail where the waters clean, I'm not sure what you're trying to achieve with this thread.

beezt3, Cheesy, et. al.

What I'm trying to achieve with the thread is unfolding before you. An ongoing conversation in which the issues surrounding foiling's potential negative issues are discussed. There are untold numbers of threads in which the god-like virtues of all things foily are laid before us... always ignoring the negative aspects. For any design idiom to be discussed fairly, it should be a balance of the stuff that works and the stuff that doesn't.

Within the context of this thread, a small margin of the latter is being addressed openly and with a good deal of balance. To that end, I'm happy with how it has all unfolded up to this point in time.

Your direct observational comments are valuable to the discussion and I hope that you continue to contribute.

 

[ancient kayaker]

Doug and Bill: I can understand why a performance-oriented boat would have non-removable/retractable foils, and why a recreational beach launcher would have something more convenient. I appreciate your taking the trouble to spell it the pros and cons.

Chris: I agree that the thread has produced an interesting and overdue discussion. There is a weed problem in some of the lakes I use but it's easily avoided. There is a shallow water problem in my closest lake that rules out foiling but it's much too small for a fast-moving boat anyway. So I don't really have a problem. Nonetheless I can appreciate the problem that others can have.

I would like to see this thread evolve into an open and mature discussion of solutions to the problem. It seems relevant to the topic. Hopefully you have no objections, guys? Or we can start another thread. I hesitate to do so as I am not (yet) a foiler. At my age I probably have no business even thinking about it ...

One thing we don't need more of is posts informing us that fouling is not a big problem in one place or what a b!tch it can be to clean off in another. If your location is that good just rejoice and keep it to yourself! Ditto to comments on the impracticability of foilers, foiler demographics and other irrelevancy.

Leaving the non-related issue of beach-launching convenience aside, there doesn't seem to be much point in being able to lift the fouled foil if that doesn't get rid of the material and doesn't bring it within hand's reach. I don't see much difference between a couple of feet down and a few inches down if it's still under the boat. In a narrow hull like a typical moth foiler it might just be accessible, but I know that in a kayak the bottom center of the hull is out of reach unless someone else is holding the boat steady. So I think my point (post #43) has been agreed.

As an engineer I refuse to accept that a solution cannot be found. My earlier suggestion of a swept-forward strut with a notch to snag the junk (post #26) is still on the table. I assume it did not get much of a response because the following dogfight got a bigger audience. Was my suggestion such a useless idea that it wasn't worth wasting the virtual paper and ink? If so, put it out of its misery, and come up with other ideas.

 

[Cheesy]

Leaving the non-related issue of beach-launching convenience aside, there doesn't seem to be much point in being able to lift the fouled foil if that doesn't get rid of the material and doesn't bring it within hand's reach. I don't see much difference between a couple of feet down and a few inches down if it's still under the boat. In a narrow hull like a typical moth foiler it might just be accessible, but I know that in a kayak the bottom center of the hull is out of reach unless someone else is holding the boat steady. So I think my point (post #43) has been agreed.

As an engineer I refuse to accept that a solution cannot be found. My earlier suggestion of a swept-forward strut with a notch to snag the junk (post #26) is still on the table. I assume it did not get much of a response because the following dogfight got a bigger audience. Was my suggestion such a useless idea that it wasn't worth wasting the virtual paper and ink? If so, put it out of its misery, and come up with other ideas.

I think the most interesting point that has been made was by Beezt that the weed (here anyway) tends to float and usually gets caught up on the foil struts, not the lifting surfaces, and then it quite often floats off in a slow tack anyway.... maybe not such a big problem after all. On a side note the R's are pretty cool, the L3s are sexy looking boats, what is interesting though is that foiling seems to be generating a lot of interest in the class and it looks like the older hull shapes may at least semi competitve again

 

[Gary Baigent]

Weed problems around foils - you have to stop the boat .... and then reverse, otherwise performance is badly effected because of huge turbulence. A slow tack will also still piss you off ... because invariably the weed will stay hooked up. Head to wind, sail backwards, no other way round the problem. But it is universal to all designs, not just foilers. Live with it.

 

[Doug Lord]

I think the most interesting point that has been made was by Beezt that the weed (here anyway) tends to float and usually gets caught up on the foil struts, not the lifting surfaces, and then it quite often floats off in a slow tack anyway.... maybe not such a big problem after all. On a side note the R's are pretty cool, the L3s are sexy looking boats, what is interesting though is that foiling seems to be generating a lot of interest in the class and it looks like the older hull shapes may at least semi competitve again

======================

I agree-thats been my experience on the Rave as well. The foiling R Class is a tremendous shot in the arm for sailing.

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I don't think you would, necessarily, retract the foils to clear them of weed-it would probably be easier and quicker to use a tool or back down. But it's nice to know you could. The advantage of a properly designed retractable system is in launching or leaving-makes that process as simple as any other dinghy rather than the convoluted process of having to walk the boat in or out -on its side-to launch or leave.
In years of sailing a Rave, my boat and numerous models in this area I have never gotten weed or trash on hydrofoils. There have been just a couple of instances of weed on the vertical fins since most of the grass/weed floats on the surface not as low down as the lifting foils.

 

[Doug Lord]

A swept-forward strut encountering a small object at the surface would lift it every time a wave passed, to where it could be snagged by a notch or hook. That could keep it out of the water most of the time. Simple, safe and just might work on bags and other small stuff.

Any more ideas out there?

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Terry, unless I'm misunderstanding you this appears like it would snag weeds in such a way that they became even harder to get off. Most Moth foils are angled forward about 7 degrees-to have the effect you're after wouldn't the angle have to be more than that?
If you're willing to go to the expense the Melges guys are you could use a little razor blade mounted horizontally(fore and aft with the blade up)-when pushed down the blade would retract and "nest" into the foil bulb; to use to clear weed just pull up and the replaceable blade would cut most weed. This is different than the Melges system in the way the blade is used but the same in the sense that it requires a track inside the leading edge of the daggerboard. Maybe it could be simplified using a taut wire just slightly recessed into the leading edge that moves the blade from its "nest" using a small hand crank?
Still sounds too complicated for the seriousness of the problem.....

 

[ancient kayaker]

Actually, I would think 7 degrees would be about right. That's about a 1:8 slope.

As a wave passes, my plan is the buoyancy of the floating trash combines with the "bow wave" where the foil strut pierces the surface to overcome friction enough to slide the trash up the strut, where it would snag in the notch. That would keep it above water except for the occsaional wave. Chances are are plastic bag would soon fall off and maybe plague the competition!

Although some weed might still trail in the water, it will skim on the surface rather than be pulled through the water at depth. So there would be substantially less drag.

I'm not sure what effect on drag a wire recessed into the leading edge would have, once the wire is moved out of the slot, and whether it would go back after use.

The notch has the advantage of simplicity.

Another scheme might be a hook on the lower edge of the wire, also recessed, which could be hauled up once during a race to trap one lot of trash above the water.

 

[bistros]

Actually, I would think 7 degrees would be about right. That's about a 1:8 slope.

As a wave passes, my plan is the buoyancy of the floating trash combines with the "bow wave" where the foil strut pierces the surface to overcome friction enough to slide the trash up the strut, where it would snag in the notch. That would keep it above water except for the occsaional wave. Chances are are plastic bag would soon fall off and maybe plague the competition!

Although some weed might still trail in the water, it will skim on the surface rather than be pulled through the water at depth. So there would be substantially less drag.

I'm not sure what effect on drag a wire recessed into the leading edge would have, once the wire is moved out of the slot, and whether it would go back after use.

The notch has the advantage of simplicity.

Another scheme might be a hook on the lower edge of the wire, also recessed, which could be hauled up once during a race to trap one lot of trash above the water.

I'm not sure all this is actually necessary. Compromising the design from the theoretical ideal to handle a potential problem may not be in your best interests. Knowing where we are in Ontario, trash in the water really isn't a problem like it is in other places.

Even if a bag is snagged, what real trouble is a slow sail to a shore line where the boat can be capsized intentionally and the crap removed? Methinks a tempest is being stirred in a pretty clean teapot.

Face it, these boats are for the most part a fun diversion into technology for technologies sake, not a mode of transportation across long or dangerous passages. Especially at the level Terry and I build things.

On large scale ocean-racing record-breaking one-off boats that are making long distance passages, crap on the foils is a serious and potentially dangerous problem. On small dinghy sized boats crap on the foils is just a temporary pain in the posterior and bad luck if racing. I would not design a boat to be sailed in Qingdao algae, nor would I design one with a garbage basin as the design environment.

Not to sound Shakespearean, but isn't this just much ado about nothing? Adding the complexity and variables involved with the questionable retractable foils is bad enough.

--
Bill

 

[ancient kayaker]

... we are in Ontario, trash in the water really isn't a problem like it is in other places...
Bill

True. Just a Canadian butting in where he thinks he can help them poor benighted unfortunates elsewhere I guess ...

... Even if a bag is snagged, what real trouble is a slow sail to a shore line ... l

Bill, I did use the word “competition” ...

...Not to sound Shakespearean...

-Ah, but the play’s the thing methinks ...

 

[beezt3]

Actually, I would think 7 degrees would be about right. That's about a 1:8 slope.

As a wave passes, my plan is the buoyancy of the floating trash combines with the "bow wave" where the foil strut pierces the surface to overcome friction enough to slide the trash up the strut, where it would snag in the notch. That would keep it above water except for the occsaional wave. Chances are are plastic bag would soon fall off and maybe plague the competition!

At speed the weed tends to stay where it is. In large waves it can migrate up, but generally it'll only move if the boat slows. But once out it stays out. All the R's are running more than 7 degrees of rake, but it varies between boats.

Although some weed might still trail in the water, it will skim on the surface rather than be pulled through the water at depth. So there would be substantially less drag.

Thats right, the drag isn't noticeable. Even weed a metre or more long blowing about isn't significant, and it doesn't seem to stay on that long.

I'm not sure what effect on drag a wire recessed into the leading edge would have, once the wire is moved out of the slot, and whether it would go back after use.

The notch has the advantage of simplicity.

Another scheme might be a hook on the lower edge of the wire, also recessed, which could be hauled up once during a race to trap one lot of trash above the water.

Even with two on board an R, unless the clearing mechanism could be operated from the normal sailing position, you'd struggle to keep foiling and operate it at the same time.

With regard to launching: the R's are using a tiny trolley, similar to what you'd use under a cat or kayak, but smaller. Sure the boat is light enough to be carried, but its awkward with two people.

 

[beezt3]

Given your wondrous Foilapedia collection of Internet posts and hearsay containing the word hydrofoil, could you provide numbers to support your position? How many Raves were produced under it's original ownership? How many have been (NOT expect to be) have been produced by the "new company"? How many Ospreys have been (NOT expect to be) produced? How many Hydroptere(s)? How many RS600FF (complete boats)? How many RS600FF foils kits? How many RS600FF Carbon? You get the idea.

My point is simple. Just because one or two boats of a type have been prototyped, the sample is not statistically significant. Measuring against a total of all produced foilers is the only realistic measure in a niche market this small. I personally would not bother with mega-dollar one-off records chasers, as they never were or will be intended to bring foiling any market volume. Can't say as I see anyone building their own Hydroptere any time soon. As well, in the case of the RS600FF what do you mean by "growing"? Is this an indication there are 15 already on the water (with the now deprecated uncompetitive glass hull) and there has been 2 carbon hulls sold? Or do you mean there are 200 on the water and orders for 300 more?

Counting "designs" isn't relevant - there may be 35 designs out there that have never made it to one hull or past the first hull. Creating a comprehensive list of all boats STILL IN PRODUCTION making it to 5 hulls may be a great place to start. Homebuilds don't count. My friend Sam Schneider's boat should not count (although it will probably end up better than most "production" efforts).

I think the quote above is a particularly good example of the first sentence of the quote below.

Statistics are slippery, and statisticians are slipperier. You have to analyze things VERY carefully and have access to all the raw data, as well as establishing a framework of relevance to be able to draw any conclusions.

--
Bill

Choosing current commercial success as your only valid criteria for implementations of ideas is certainly your prerogative. But in a historical context seems a little contrived when talking about fast moving development classes.

Anyway back to retractable foils: it looks to me like you're all correct. Phil S raises valid points that do need to be addressed if retractable foils are desired. Most R's and Moth sailors seem prepared to trade off a certain amount of practicality launching and landing to reduce weight and complications during racing.

Not everyone may be prepared to do that, and its early days. Various people have expressed an interest in retractable foils (Ancient Kayaker being one). They'll have to overcome the issues Phil S raised. If a restricted class chooses retractable foils everyone is in the same boat. Plenty of people are prepared to accept all sorts of shortcomings and compromises in restricted classes. If a more open class has them, people will choose to use them as is, not use them or fix any shortcomings as they see fit.

One of the R's does have retractable foils. But they don't retract them unless the tide is low. Everyone else just tries to avoid hitting the submerged rocks in the launch area, with varying success.

Boats over a certain width won't be practical to launch capsized as you won't be able to walk deep enough. Some of the R's are close to that limit.
I suspect Mirabaud is one of those craft over the limit, so I presume they have a practical solution.