What some people do for fun...

[IRGuy]

Try this sometime..

http://www.youtube.com/watch?v=B2PQfJ2SAg4

[Harry Babb]

Hey Ya'll......hold my beer and watch this! ! !

[Rawleigh]

I fail to see the point or the thrill!!

[randall]

i'm far more interested in the keel design. i'm assuming there are two or its moveable. cause it sure aint parallel to the mast.

[In Memory Walter K]

At one point it seemed it was perpendicular to the hull, so I think it may be moveable.

[Stephan]

Guys-
The keel is canted by a large hydraulic ram. You may notice a bulge at the keel/hull intersection which is the bearing for the keel. For this video they have retracted the daggerboards (you can see the exit for the Port one in the B). By the way -That's a boat he races single-handed...
The crew for the photo shoot must have been working furiously to keep the boat in that balance as the shape of the hull will force the boat to round up into the breeze when it heels like that. Note the tiny transom hung rudders, bright orange like the keel, the port one is folded up. The Starboard rudder is far too small and its orientation usless at that angle of heel so they did it all with sail control.
My awareness of this stuff is dated enough to be dangerous but the foil supporting the keel bulb is generally a neutral foil of minimum dimension to the rule or structural necessity. The daggerboards are the foils with the ability to deploy them deeper and reduce slip angle or shallower and increase slip angle but also increase angle of attack of the daggerboard and therefore lift potential....

Sorry...

also http://www.yachtsponsorship.com/2009/05 ... ctivation/

[Stephan]

Randall-
Here a shot of a keel foil for a 90'. That's a little over 15' long. I'm told it was formed from a single billet of unobtanium...



Note the attach point for the ram at the top... that's where the load is and I understand everyone who's ever heard it go bang knew exactly what just happened...

[randall]

thanks stephan....thats kinda what i figured. the next question is it computer controlled like a stealth fighter or can a human have enough "touch" to keep it in trim. especially solo.

[Stephan]

Randall
The one's I'm aware of are manually directed and not dynamic.
However the modes (foil configurations, sail selections, etc.) for the boats are entirely computer generated and the sailors execute the calculated modes and then use their skill to see if the computer model is optimizing the result or if they can devine a better combination. Every so often some campaign comes along who believes they can do it all with computer modeling, but...
You touch on a lot of the confusion about these systems though. These developments as well as others are consuming huge amounts of energy as the boat races around the course. Not jokingly it has been suggested that two crewmen grind for the entire race so there can be enough hydraulic pressure to reconfigure the boat.
Hey, one man's progress is another's sacrelige...