Speed Record for hydrofoiling ?

[bragnouff]

Isn't there a hard limit due to cavitation effects?
Whereas things that essentially skim the surface aren't that affected, provided they can control an enormous amount of power?

[Slyde]

45 knots James Johnston has big balls. What foil was he riding?

[cglazier]

On race boards (remember them) the very best riders whould ride with their boards edged away from them so their fins were the only thing in the water. This was like hydrofoiling but on the fins. Soon we all figured out that an actual hydrofoil setup worked even better.

On the speed boards that are currently used when going for high speeds, the fin is really of whats in the water along with the edge of the tail (as Peter says above) so really it is almost like hydrofoiling. The classic hydroil shape that we are familiar with has two wings, a fuselage and a mast but is certainly not the optimum shape for speed. Probably a J shaped hydrofoil like you see on Americas Cup boats will be the shape to set new speed records.

CG

[ronnie]

On race boards (remember them) the very best riders whould ride with their boards edged away from them so their fins were the only thing in the water. This was like hydrofoiling but on the fins. Soon we all figured out that an actual hydrofoil setup worked even better.

On the speed boards that are currently used when going for high speeds, the fin is really of whats in the water along with the edge of the tail (as Peter says above) so really it is almost like hydrofoiling. The classic hydroil shape that we are familiar with has two wings, a fuselage and a mast but is certainly not the optimum shape for speed. Probably a J shaped hydrofoil like you see on Americas Cup boats will be the shape to set new speed records.

CG

A J shaped foil holds the current world record on VESTAS Sailrocket 2. @ 65.45 knots

J shaped kitefoil.


Foil that automatically controls it's depth in the water.


By having a clutch on the bar that you could lengthen the lines to the centre of the kite with, you could change the kite shape from more of a Y shape to more of an m shape, so effectively you could make the kite bigger and more efficient as you went faster, to compensate for the extra drag of the foil.

[gbrungra]

Kite hydrofoils already rule in efficiency-limited situations. Speed boards still win in control-limited situations (very high winds). And Sail-Rocket got to the next level w J-Shaped super-cavitating foils.

I’m interested in this topic for bragging rights for our sport, not participation...

[Peter_Frank]

45 knots James Johnston has big balls. What foil was he riding?

I dont know, but he rode a Spotz when he reached 40 knots, years ago, using a 10 m2 F-One Diablo, but have ridden Taaroa Swords and tried several others Mikes Lab and Enata/Banga, besides F-One now, for the 45 knots.

I dont think it is the gear that much in this respect, when using a good race wing not too big, but the rider primarily, and James CAN ride extremely fast always, on almost anything, so you are not in doubt when you see him on the water here on the downwind legs

The younger guys around the world has difficulties following ha haa, respect

Peter

[andyjiggs]

I can only imagine the carnage of wiping out at extreme speeds on a hydrofoil
Respect to anyone who has the skills and balls to lock in and hang on.
Sounds intimidating to me........
Must be getting old

[Hugh2]

The sailing record was only elevated that high when they figured out special smaller foils, and the trick in part was then getting past the lower speeds to where the smaller foils started working. If you watch the video it is still scary as hell on the edge of control, and that's with multiple contact points, not a single foil.

[plummet]

I can see an advantage of the hydrofoil compared to the surface board. The surface board needs butter flat water with stupid wind on an exact angle. In reality it needs a special trench or a magical spot where the land follows an arcing broach reach trajectory. Surfaces boards a limited to this magical location.

A hydrofoil on the otherhand can go real fast on rougher surface water opening it up for a wider range of locations and giving it the option of the perfect trajectory. If cavitation and mast drag can be overcome with some funky design then I think we will see some stupid fast hydrofoils.

[bragnouff]

Here's a nice bit of reading about SailRocket and attempts at punching through the 50kts cavitation barrier. With foils profiled more like a wedge than a classic teardrop.
https://www.wired.com/2013/01/ff-paul-l ... ailrocket/