allipp01 
05/19/16 #19312
With all the hype of the foiled SUPs showing up on social media recently, I've been wondering about a foil for a surfski.
I don't think a ski would balance well on a single foil, but would a single foil in the front be sufficient to lift the nose out of the water and prevent pearling? Do you need a foil in the back also? How would you steer if the whole boat, including the rudder, lifted out of the water?
Anyone have any thoughts? Tom Swetish?
Sean 
05/19/16 #19313
Sean Stimac, LEED® AP
Michael Van Derwater
05/19/16 #19314
Alan. The answer to all your questions right here. :)
(Link no longer valid)
Seems like these guys have been playing with this idea for quite a while. Me being a sailor before I got in to paddler saw this innovation happen with the the moth sailboat design a while ago, which is now a pretty common racing class. Only a matter of time before this is on surfskis and maybe outriggers. And I think that surfskis and OCs could generate a lot more power than a SUP getting you up on the foil much easier. The questions is, how do you size your paddle?  …
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-Michael
Tom Swetish
05/19/16 #19318
My gut says a larger main wing just forward of your c.g. with a smaller foil near the stern to control pitch. Take some inspiration from the last Americas cup. Tough thing is that we don't have the same ability to shift body weight that a sup or kiter does. Still, I'm almost compelled enough to give it a go. If those Flyak guys had Bellingham waves, maybe they could have foiled without needing Greg B for a motor.
allipp01
05/19/16 #19315
I've seen some of those videos of the kayaks flying in flat water. I'd really love to see how they perform in the surf!
Michael Van Derwater 
05/19/16 #19316
Thats what I was thinking. Even a little lift could make a huge difference in connecting waves. With a foil I would know what its like to be Alan Lipp. :)
-Michael
dnjacobson79
05/19/16 #19317
There is a guy in Stevenson who put a foil on a ski. Austin and I have seen it, none of us could foil well enough to get it up. Enough said, but those youtube k1 foils seems cool.
I bet Don K has something in the work……DJ
John Rybczyk 
05/19/16 #19319
Those foils would be great at harvesting weeds in the bay!
Reivers Dustin
05/19/16 #19321
From my air-chair experience: very difficult* to balance, also transition from displacement to flying very difficult.
*very difficult - as in, ridiculously hard, even with hours of training. Without control system, plus feedback variable plus control variable surface, then the foils must be fix-tuned for specific speed and weight. If tuned for stability you sacrifice lift (therefore increase drag, therefore increase power requirement). This is a wonderful engineering problem. A great example would be aerodynamics control problem for airplane wing with perturbation. As they say, “you can make a box fly if you have enough power”. -The problem is the engine.
bill 
05/19/16 #19320
Exactly.. If you think your surf rudder is a weed magnet just follow one of these around and you'll never have an issue again. At least until it comes to a weed laden halt. Then you get to watch the paddler get out the mask and snorkel to clear the foils. Plus it looks like a swim start off a beach launch…. I beginning to see why it might not be very practical around here.
Bill
lori & beau whitehead 
05/20/16 #19322
The SUP guys in the vids “pump” a lot to keep up their speed and keep the foil engaged… that might be tricky sitting down. The back 1/3 of the downwind boards are also chopped off to keep the tail from dragging. Fun to watch though for sure.
GoFoil is selling these (foils only) for $1600 and they are back ordered for 6 months. Wether they work or not, they are making a pile of money.