I would steer away from any coating over wood even marine treated. My father-in-law was in the boat business and I've seen high dollar Sea Rays just a few years old with rotted decks. They use a marine plywood and it just won't hold up like good old oak or hickory or some other hardwood. Fiberglass over wood holds in the moisture. You want the wood to breath and dry out.
Just my 2 cents...
