Personally, I believe both the windsurfers and foiled proas will beat 50 knots, only the proas have more room for improvement, so could do it earlier. All windsurfers can do is reduce the drag from the crew's body. Foiled proas may still explore supercavitaing foils and different sail shapes. Structural issues tend to be minimized by better technology.

I second the Rolf's question about YPE cost of materials. Shouldn't be so much, after all it is a small boat. From what I read, it is the sail that is complicated, difficult to build and expensive. Anyone knows how much they spend on the toy yearly?

Luiz