Toby wrote:but damn, that's it for the kiters...or not?
Sebastian Cattelan has recorded 61.25 knots over a 2 second interval at Luderitz, so it is possible for kiters (and possibly windsurfers) to get above 60 knots for 500m if they have perfect wind strength and direction and the water is also perfect.
There is a doubt about the windsurfers though because the Sailrocket used to be limited by cavitation on their hydrofoil and they put fencing on the foil to reduce the aeration. The windsurfers may run into a similar problem on their fins, but if they dont then they are also in the race.
Correct me if I'm wrong but cavitation for foils starts at 50 knots, and what I think sailrocket has done is redesign their foils so once they reach a certain speed, the entire underside of the foil cavitates, so you have reduced drag when that happens, but below 52-53 knots this cavitating foil induces a lot of extra drag as the cavitating bubbles loop back into the foil. At least that's one theory. I'm not sure anyone knows exactly how their foils work, because they are not working via a modelling program (found it didnt work for their situation), they tune the foil and go out again over and over again. They've been doing this for ten years . . . . So they are doing something really advanced here, that nobody else in the world is doing, and all from a practical standpoint not really any theory. It might be years before we really understand why this particular foil lets them break through the foil barrier of 52-53 knots. I dont see hydroptere ever catching them, it's going to take an entire boat redesign for a megayatch foil to get up to sailrocket speeds.
Of course, kiteboards right now are not foiling, they are planing, so theoretically the only top speed for kiters is how much wind we we get in luderitz and the size of their balls.