Actually, airplane foils work just fine. As it turns out, the greater density of the water almost exactly makes up for the lower speed. Reynolds numbers, and such like that.

I've used all sorts of templates, measurements, guide lines, scoring, etc. and I've concluded that if it looks about right, it's gonna be darn good. I may just trust my own judgment for a change next time.

: Good old eyeball, and a little established technique. Eyeball for the general
: shape (airplane airfoil, since I don't know what in the hell I'm doing
: around boats), and starting out with facets or chamfers for symmetry. Same
: as when you're fashioning a round spar, and start by making an octagon,
: then a 16-a-gon, 32-a-gon, etc. I can count up to octa, but then I'm lost.
: But I'll bet you know their real names.

: Cheers,
: Kurt