I haven't had too big of a problem with my Nacra 5.2 turtle-ing. Seal the mast, and be quick to jump on a hull.

Couple benefits of the Nacra 5.2:
1. Racing, the Portsmouth rating is very favorable. Pull off the jib and race it single handed and the rating barely changes. In 3ft chop you can stay with Hobie 20s up wind or atleast I have.

2. Cheap... $1300-$3000

3. Solid construction and company support.