Interesting!

So to take it a bit further, would dihedral or anhedral be appropriate? Stealth seems to have a slight anhedral.

There are virtually no weeds where I sail, so I suspect it would be appropriate to have very little or no sweepback. Does that sound correct?

What about the aspect ratio, tip shape?

Since the foil would be used to keep the nose from digging in and flying up I assume it would be symmetrical.

I envision a foil about half way up the rudder, to prevent rock rash and reduce the rudder side bending moment arm. The foil shape (airfoil is the name in an aircraft) would be symmetrical.

I also think that a temporary mounting plate so that angle of attack could be investigated (adjusted) would be in order.

Any thoughts?