Hydrofoil dory is a neat idea -- and possible plausible. The hull is light enough to lift easily. 

I've been sailing my lug-rigged dory hard and have gotten it up to more than twice hull speed (hitting 13 mph). I'm confident it will go even faster, but the wetted surface area is a limiting factor. I try to get my weight as far aft as possible on a reach and even so I can't get the bow out of the water. A foil on the rudder would seem to be counterproductive as it would push the bow down. A couple of foils up by the mast might do the trick. . . . But what do I know? Just guessing.

   Birch2,

I had the opportunity to have another dory sailor watch my dory under sail.  I have red bottom paint up to the water line with off white hull so it is easy to see the foreward/aft tilt of the boat under sail.  Even with just me in middle seat the other dory sailor told me my bow rode a couple inches high and with my wife in the stern seat the bow rode even higher.  Mine is a lug rig and the other dory was a sloop rig but both of them rode bow-high and our conclusion was with 2 people in the boat that we needed to use the foreward and middle seat, not the middle and aft.  When sailing alone using the middle seat I tried putting 6 milk jugs filled with water in the bow and that did flatten it out a little.  The other dory sailor and I did find out that the more you can get the bow down to nearly a flat water line so the stern doesnt squat, the better the boat comes around in the wind.

Your thoughts?

Curt

���Fascinating. Perhaps the bow rides high because the boat is trying to climb over the bow wave. That's what happens with a motor boat. Does the boat flatten out at high side? 10 mph or so?

���Meant to type "high speed"