You're very kind, Gary.
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<br>Actually, by posting it to "the public domain" I've just made it un-patentable. Now it belongs to the world.
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<br>{.....Hello?.....}
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<br>{......... World? ......Are you listening? .......}
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<br>Hmph. Seems like the world has better things to do. :-)
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<br>Yesterday, I had the audacity to call up Randy Smyth with a suggestion to put cams in the luff batten pockets on dacron sails and run a string up through all of them, so you could tighten or loosen your whole batten set with one pull. If you had trouble keeping the string outta the air flow, you could put a flap over the string, and fair the resulting slightly fatter luff into the mast with long rubber stick-ons, which would also actually improve windward-side mast-sail transition.
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<br>He was also very kind, didn't laugh a bit.
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<br>Of course, I didn't hear him drop the phone and go running off, shouting "Bill, drop everying! We've got new luff pockets to design!"
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<br>Good thing I have a day job! :-)
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<br>Sail Fast!<br><br>

If it is ok to use asymetrical daggerboards or to apply an angle of attack to symetrical ones, then the next step is to tilt the boards from vertical, say 45 degrees, obtaining some vertical lift.
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<br>By doing so, we get the advantages correctly listed in this thread AND the vertical lift. The vertical lift raises the boat out of the water, reducing the wetted area and enabling planning at lower speeds.
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<br>If we want to avoid "tacking" the daggerboards, why not use a trimaran with the amas slightly higher then the main hull so that when one board is in the water the other is (at least partially) out?
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<br>If this sounds good, take a look at aegeanmarine.com and you will see an american made hidrofoil assisted folding trimaran that has exactly those features.
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<br>Fair winds,
<br>Luiz
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<br><br><br>

I loved the Ageanmarine site, and wish I had a hundred large to drop on a hot boat. I did think the most lift was generated by the 3 planes on the boat, but you're right, those boards sure are tilted!
<br>Actually, Luiz, as you know, on a cat, the boards do tilt somewhat when you fly a hull...
<br>Of course TANSTAAFL applies; every ounce up is an ounce less lateral resistance...
<br>I wonder if Wouter or Jim Boyer could tell us when you might expect to hit the sweet spot on tilt?
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<br>Sail Fast, or at least often!
<br>Ed<br><br>

Actually never like this for the tilted sail pushes the boat back in the water again. when the sail can be canted to windward then you might have some benefit. But most practicall soloution still is to keep the non cantable mast and to tilt the boards in the hulls
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<br>Once again everything is a balance and you should always look at the complete picture.
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<br>Wouter<br><br>

The purpose of boards is to prevent slip, and slip along with the apparent angle of attack causes drag on the boat.
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<br>If you cant the boards you are effectively removing some of the resistance to slip, in favor of raising the hull.
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<br>Has anyone seen any studies that compaired the reduction in drag from less wetted surface by raising the hull, as compaired to increased drag from additional side slip.
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<br>I seem to remember reading a article several years ago on canted hulls and it refered to this effect on the boards angle
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<br>
<br>Matt
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<br><br><br>

just to butt-in, but wouldn't a boat that has conquered the lift slip problem be called a hydro-foil? like the trifoiler. I forget where, but I saw a hobie 18 with hydrofoils, looked fast but I don't know the details.
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<br>Tim(cheech)<br><br>

You don't need 100. Buy a smaller one directly from the designer/builder.
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<br>When I asked 6 months ago, the Catri 23 was 27,000 standard and 42,000 complete and delivered to the US.
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<br>Check the european Catri site at www.multihull.de/catrimarine
<br>or ask the price directly to the builder:
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<br>CATRI MARINE - PHL
<br>Tel. + 371 9128054 , fax + 371 7258427
<br>Box 120, Riga LV 1063, LATVIA
<br>E-mail aldis@catri.apollo.lv
<br>
<br>Have fun!
<br>Luiz<br><br>Luiz

This is just to bring the old post back...

Since you brought it up....here is the URL for the foiling Hobie 18, foiling Hobie 16 and my woodie, an old A-class cat. . A tilted surface piercing foil works best in my rigs when it runs about 35 degrees to the water: more vertical and there is less lift. These rigs are great fun; by the way, weight and drag are the sailing hydrofoiler's biggest enemies.

I'd love to have a set of foils on my boat, it looks like a blast

Wouter,

Recently Aldis Eglajs had to solve this problem in order to fit daggerboard-style foils to a Catri. His solution (as usual) was very simple and clever - the kind of thing that you say "why didn't anyone think of it before?".

I am really sorry that I can not describe it - but he may want to ask for a patent.