I have mate with kite foiling outfit and he's got up over 40knts recently. Can sailboard foiling in future match this. Less wind is required and snall chop does not matter so much, it could end up a safer option than a fin at high speeds as the gear develops
As in the 53.xxkts? I'd be very very surprised. There's a few people at the moment trying to break 40 on a windsurfer which will probably happen with the small foils they are developing but 50 is a whole other ballgame. The laws of hydrodynamics work against you pretty badly at those speeds.
Select to expand quoteCJW said..
The laws of hydrodynamics work against you pretty badly at those speeds.
The SailGP boats are doing 50 knots on foils though. A windsurfer being smaller will be twitchier but everything else is in the ballpark. Maybe just need faster electronics in the pitch control. Is electronic servo control allowed in windfoilers?
sailgp.com/about/f50-catamaran/
"Rudder pitch will be actively controlled allowing the trim/attitude of the boat to be set irrespective of the ride height."
Yeah true, they reckon the F50's foils cavitate at 48kts but can power through it a few more knots. I'm sure if they designed specific speed foils they could go a bit faster. I'd suggest though an F50 has a way more efficient power source in their solid wing, and way more righting moment due to the platform layout and differential rudder rake. Given a windsurfer can't hope to get near that, can you design an efficient enough foil at those speeds? I believe the one phantom have designed for their 40kt attempt is around 300cm^2 or something like that....which is about 1/3 the area of a normal race foil. Next becomes the issue of actually controlling it? As for it being safer, I'd expect the crashes are going to be extraordinary 
At record speeds, as CJW said, what happens under water gets very weird. Vestas Sailrocket had to go to a wedge shaped wing at those speeds.
www.sailrocket.com/node/288
+1 on the control issue. I'm thinking the next technological advances will be in body armor
Control is my problem at only about 15 knots. I'm surprised you fellows are as stable as you are. Not like a windsurfer that's pitch stable, all you can do is lengthen the fuselage to slow down the pitch instability. Why not use a bit of electronic wizardry to create a virtual longer fuselage? Just measure the rate of change of pitch and apply a bit of tail trim in the opposite direction. There's plenty of room in the fuselage for batteries, electronics and servo motors. You could dial up a "longer " fuselage once you had it up to cruising height. Back it off with a boom-mounted dial when pumping or negotiating swell. Or go all the way and incorporate a height transducer. Set and forget. Sail it with as much concentration as it takes to sail a slapper.
if they can make control systems to keep a tiny drone stable in gusty winds then the control system to keep a foil at a stable height going 50 knots should be easy. They're doing it on larger boats already. Windfoilers might need a bit more wind and to be going a bit broader than the F50s. F50s do 50 knots in 20 knots of wind. A windfoiler might need 25-30 but I reckon if enough of those brave Frenchmen decide to have a crack at it, it will be done.. eventually.
