You read and quoted too fast. Pay atention:

I wrote:


Williwaw was a one-off cruising foiler, not a production boat.

The designer of the Catris, Aldis Eglajs, also built other cruising foilers before, including a cruising proa with foils in the 80's, but all were also one-offs.

The first production foiler was either the Rave or the Trifoiler (I am not sure which came first). The Catri is the third production foiler, but the first with a cabin.

I guess they remain the only ones to date (?).

Cheers,

Darrell;

Why were the solid winged masts rejected?

Also do you know why windsurfer style booms not used, or never caught on?

Always wondered about that.

Their is a foil 18 foot Skiff @ Sydney Flying Squadron (18 foot skiff club)in Oz.

It has an L shaped foil at the end off each wing that angles inward. They have no flaps and retract towards the hulls when coming into shore.

The rudder is a T foil with flaps that are adjusted through the tiller extension.

Last time I saw it, they were still working on some stabilaty problems but looked very quick with the kite up and in full flight.

May have to put foils on my Tornado now

First of all, it's a real pain the butt to reduce sail area on a wing mast!..not to mention very expensive and fragile. Allowing wing masts on an A class cat would have made performance greater but would not have helped the class grow.

I had a dream of sticking a wing-sail on my Rave for a period of time. It would be a giant hassle - extremely impractical. Like an earlier poster said - how the hell would you store - or even rig a wing sail for regular use?

One line of design I explored was how to make it cheaply. The commerical shrink-wrap plastic (used to wrap boats) seems like an ideal, cheap method of sheathing a wing sail. Just make a light, rugged frame and you could wrap it with new heat-shrink plastic for every race.

In any event - my sails currently offer all the speed I need. A strong gust into the Reacher on my Rave boat has lifted me and my boat clear off the water. Kinda scary, but when your boat is as light as a Rave - it can do that.

That leads me to one important point that a lot of people are not mentioning about foil craft - they need to be light. I'm surprised to see such heavy crafts (like the Catri and Williwaw) actually foiling. Getting the Rave to fly is relatively easy, but you do need stiff breeze - you must need a near-typhoon to "fly" a heavy boat like the Williwaw.

Cat boats would seem to be well suited for foiling. Trying to get a boat to multi-task may not be an easy job. Items I've bought in the past, that attempt to perform multiple functions, never seem to perform any of them well. Specialized tools work best for specialized jobs.

The post above reminded me of the rack they used in San Diego for Dennis Conners Cat with a wing sail. Rather than de-rig it, they just locked it into a rack and rolled it over on it's side for storage... That cat is 60 feet long. They had two of them. One with the wing and the other a soft sail.

Reference the wing sails, hang gliders have been double surface for a very long time. It's not rocket science.

You can fold an 36 foot wingspan glider into a 18 foot by 1 foot tube that you throw on top of a car and then throw into the garage.

I'm not sure of the state of the art in design, but when I last flew, my glider was about 20 minutes to rig and about the same to derig. I believe that it's considerably faster now with the new designs.

Most gliders had the ability to vary the geometry of the sail with some sort of pulley or lever. You could spread out the wing thus tightening and increasing the span giving better high speed and flatter glide. Loosening the wing gave better landing characteristics.

A hang glider is considerably more complex than a sail, as fractions of an inch in sail shape can spell the difference between a docile machine and a rocket ship from ....

Speeding through puffs into lulls is a problem in keeping foilers moving well. The engineers who say it will never work note that the dynamic of fast moving air and a fast moving foiler is always changing: I have to sheet in and out some on my A-class soft sail to keep the twist working and the rig flying. I should think a solid wing mast would be a nuisance under puffy conditions. Real life ain't no wind tunnel with linear air flow!

Not good news for Rave and Windrider sailors... Looks like the mother company "Confluence Watersports" who builds the boats http://www.confluencewatersports.com that includes Wilderness, is having big problems. They have been suffering problems in sales, laying off lots of staff, been in patent disputes and had CEO hiring legal problems. The company has been canceling dealers pre-season order discounts, freight allowances and is canceling orders with little notice. We have a dealer that had a truck load kayak order canceled just one week before expected delivery. They were told to look to a another supplier for product.

Here is a link to some of the issues involved.

Problems with Wilderness

They pulled the plug on their forums shortly after I read what was going on there. Maybe they will clean it out and go back online?

May be a supply problem for a period of time.

Dave

I've never heard an engineer (worth his salt) say or even admit "It will never work". Of course there is diminishing returns.

However, most sailboat sails are such an inefficient foil.

There are an infinite number of foil sections that could be used and an infinite number of construction details that could be incorporated into a wing sail.

You could make the sail have an inflating leading edge (coupled with battens) back as far as you would like, as the "Wills Wing" "Ram Air" hang glder did.

They simply had a scoop that collected the air. As the glider went faster more air went into the foil which of course stiffened it.

You could also have wing warping as the "Wright Flyer" did and as do modern hang gliders. This is easily accomplished with pulleys etc..

As far as wind gusts, all aircraft deal with them. Wind tunnels are only for prediction.

All you need is a designer to look at different concepts and then look at the people around who have grappled with the same problems.

Wind surfers were using (I don't know if they still are) double surface to increase efficiency of the sails.

Actually wind surfer sails all have an instant aeronautical advantage over sail boats. They all have a sleeve which slides over the mast. Just this sleeve is an advantage because you get a linear flow of air from the mast on back. You eliminate the interference drag of the mast / sail connection. When you consider the airfoil has disrupted airflow right from the mast, this has to be a large drag component.

As far as speeding through lulls is concerned, soft sails I would predict would be very inefficient because in a lull they can flop around whereas a stiff airfoil is not prone to flap and consequently doesn't waste energy doing it. That's (one reason) why mylar sails are used. Whenever you hear your sail flap, you are hearing energy dissipate. By placing the mast at the correct spot (In a wing sail) you eliminate a lot of the fighting with the sail that we do when sailing. This fighting while very macho (requires pulleys etc.) is really a waste of energy.

BTW there is a nice pic of a wing sailed cat in Jan. 2004 Popular Science page 40. An ad for Canon digital printing. While it is beautiful to look at I can see where a solid wing mast like that might pose logistics problems in high winds and when storing.

However after saying all of this about that, I completely understand why wing sails were disallowed from racing. At this stage in development, the concepts put forth are not practical from the point of view of the average racer, similarly I suspect foils are regarded in the same light.

That might mean all us Rave owners have a very special boat. I think they should talk to Hobie VPs and sell the Rave design / line. I think it's a slightly better control system than other designs I've seen.

Confluence is not going to "dissapear", regardless. At least not tomorrow.

I believe that "solid, articulated wing masts/sails" were rejected by the "A" class due to the potentually HUGE costs that would been incurred by the sailors to remain competitive, if and when some one set one up and used it successfully, they would have wiped the floor with all non wingged A class cats thereby, at one step making every other A class in the world obsolete. This obviously had the potentual of, not improving the class, but of totally destroying it. The same reasoning can be applied to the "C" class catamarans! You will never see them sailing around in great numbers at a club level, it requires an irregular, prestigous International challenge, just to get two on the water at the same time.
Darryl J Barrett

Ok- Enough of this foiling talk, talk, talk. I am putting Cheetalope, the little A-cat in the water this fine warm breezy Saturday morning to zoom past the windsurfers & fly both hulls while hydrofoiling! The Rave parked next to me (Lake Santa Fe, N. Florida) will probably sit there unused & lonely again- all day, all week & all month, just like last month.

OK so are ya mice or men? Check this foil out!

http://www.humanpoweredboats.com/Photos/HydrofoilHPBs/SilverSwan_3.jpg

The question is not of mice and men. Its' of "Well, how much is this model?"
http://rinspeed.com/pages/content/framesets_e/bedouin.html

On the left at the top, click on the button "Concept Cars"
Then, to the right of "Splash" photo, click on the button "Photos"

So what kind of mileage doe it get?.... Just kidding of course.

Are they real photos?

Yeah, it's real and they've sold one already at, I think, $235,000US. I saw one on exhibit in London. I think that was the ONLY one to be seen. Rinspeed is the company that hotrod's the Porches. It seems to be well engineered with no compromises for being able to haul butt on land or water. With the sinking dollar I believe that $235,000 has grown to $250,000US today.

Hobbyists used to advertise carbon fiber horizontal foils for these pedal jobs, with an integral CF prop on a prop shaft in the middle of the lifting foil.

The older rigs were catamarans, which meant even more lifting to be done. Olympic bicycle jockeys & speed skaters and the skinny guy who pedalled the Gossamer Condor across the English Channel are panting for this job.

Just read Lance Armstrong's book "Every Second Counts" so I'm all pumped up and ready to buy one!

Whew that was exhausting just saying that!

Does anyone sell, or is it advisable to even consider putting a foil on the rudder of a Tiger? (for preempting, possible pitch pole problems popping up)