Curved Banana Boards-Little America's Cup

Patient Lady apparently made big gains using boards similar to the curved daggerboards on the Open 60 trimarans.
As in the larger boats the idea is too reduce hull immersion not fly the whole boat.
See: http://www.cclasscats.com

See my next post for info on A Class hydrofoils...

[SailDesign]

I heard this morning that they are now only some 2% off Cogito's performance. The banana boards are intersting-looking, for sure.

Steve "semi-official measurer to the Little America's Cup"

Steve, do you know any details like how close to level is the bottom foot or so of the board when it is all the way down and the boat is flying a hull?(lee board of course) Very interested!
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Just discovered the Aussie Aclass forum at:
http://www.users.bigpond.com/aiadca
Click on "Letters" then on the forum url then on "General Discussion" and finally on "hydrofoils".
They are having a discussion on the merits of and a definition of "hydrofoils" motivated in part by the phenomenal Moth on foils which is faster than an Aclass cat off the wind and "catching up upwind". Fascinating....

[SailDesign]

Doug, I _could_ tell you, but then I'd have to shoot you...
The boards are definitely banana-shaped (and appropriately coloured), and while I didn't see them in the boat, I don't think I'm giving away state secrets to say that the radius appeared around 24", and the hull is maybe 18" deep. The top and bottom of the slot is pretty much vertical, so you can do the math.
Enjoy,
Steve

Steve, w/o any shooting could you tell me the length of the boards?

[SailDesign]

You're going to have to do the math (again, to avoid getting shot) but the total arc was about 160 degrees. You have the radius, the rest is easy
We really didn't do any measuring on the boards (they curve inwards, and therefore are not increasing the beam so we can ignore them) so this is simply what I remember from seeing them briefly this morning. If Steve Clark is reading this in between the other stuff he is up to this week, perhaps he can confirm (or deny) any numbers that aren't top secret. Steve?......

Thanks, Steve!

[Steve Clark]

No one has to die.
Boards are 84" long
Radius is 80"
Chord is 10.25"
Hull is 20" deep.
At 12.5 knots they are designed to provide 250 lbs of vertical force.
SHC

[SailDesign]

No one has to die.

That's a relief! I'm amazed at how far out my initial guess was, though. I did see the boards again last Friday, and realised I was way wrong, but had not got around to re-guessing and re-posting.
Thanks, Steve.
Steve

Steve(Saildesign) now you tell me!
Steve Clark, thanks!

[SailDesign]

Doug (Lord) - Sorry, mate - Busy weekend. I'm still half sure Lars put out a set of "teasers" for unsuspecting Rubes to see.

Steve