Check out this video of the L'Hydroptere, a sail-powered hydrofoil This would make a great Phlatprinter project!
I love hydrofoils. Been studying them for a while. I've never actually rode on one yet, but did ride on a big catamaran ferry a few times in Hong Kong. Posted some plans to get you guys started: viewtopic.php?f=220&t=1690 -Kwok
Yo'd think if they were setting a speed record the crew would lay down, hide in hull or whatever to minimize drag