> Even if I lay fiberglass worse than anyone else. I can not believe
> that anyone could build a panel to survive an impact with that fist
> sized rock in an estimated 4' (real 6') surf.

You could start by looking at the fiberglass ice breaker hulls. They take some huge forces without damage. Myself, I've layed up glass that took the impact of about 600 lbs falling from two feet repeatedly, survived hundreds of miles of washboard roads carrying around a hundred pounds of lose metal, and even handled a 30mph automobile collision without damage. It's not hard to make fiberglass very strong.

Now if you want it light at the same time...that's a different story.