How much does the Fox weigh? Maybe it's too heavy for the design. The Nacra A2 is only 165 lbs. and the Blade is 230. Still, I don't think wave piercing hulls do well out in the open ocean in 20 knots and big waves. The bows may be wave piercing but the beams and mast aren't! In those conditions long, fat bows like the Inter 20, are better.