Tomahawk

jib could be very handy, I've wondered about this on moths (although will freely admit to being too lardy to have sailed a foiling one!) - should help with the flow over the back of the mainsail especially in the transition phase between foiling & non-foiling. Could really help downwind in this respect and possibly allow much larger angles. I thought the main on the show boat was quite a full cut (but I'm no expert), and sail dev was something mentioned as work in progress.

Does the foil ventilate due to proximity to the surface, or due to increase in velocity?

My guess is that it'll ventilate as the foil nears the surface and the hydrostatic pressure drops. Below that you'll have lots of drag off the transverse ridges - a bit like the step on the Cherub on the Spy Photos thread, actually.

The Cherub's drag will drop as planing is achieved, and I'm thinking the stepped foil's drag might drop once ventilation occurs. Again, interesting stuff, and l look forward to seeing how it works out in practice against conventional planing boats. My guess is slower in F1, 2 & low 3, quicker thereafter - till it's weed-bound. Anyone know how the foiling Moths cope with weed, or are they so quick and their foils so sharp they just cut through it?

Originally posted by hollandsd and the fish doesent fair to well either

You've got me worrying about the damage my daggerboard may be causing now.

Certainly used to worry me when grebes dived ahead of our passing when we were in Holland, but they always seemed to pop up behind us again. Then again, they're probably smarter than fish.

Another case for highly-raked foils...

Originally posted by hollandsd the fish can aparently hear a normal boat coming due the inherant noises produced when planing, but when a foiler moves through the water its so quiet and fast the fish dont know what hits them.

Are fish intelligent enough to know the difference between a normal boat and a foiler?