All or most of the water action is on the leeward side but it's hardly noticed until you're in 10 knots or more. Then the amount of heel brings more water into the frame, but you start to lose the sails and the boat(you've gotta have ample boat in the shot or it doesn't work as well).

A slower shutter speed can blur for a feeling of speed(that can be hokey too though), but can you hold the camera?

Some sort of gimbled tripod, deck mounted but able to slide out over the water, that's what we need. Or Onne Van deWhal(sp?) on his day off maybe.