Re: Help with boat flooring?
You don't really want to put a Band-aid on that cancer do you? When there's rot like that in a boat it's usually widespread under the decking.
You may want to consider removing all of your decking and checking everything for more rot and wet foam. Your boat is unsafe if you have rotten structural members below deck.
As far as sealing your deck:
The urethane that was mentioned is unsuitable for fiberglass boats, it works ok for aluminum boats but will be an inferior build for a fiberglass boat.
The CPES that was mentioned is not needed, it's very expensive and also has a hazmat charge on top of that... and do you really want to be futzing around with something that is that poisonous?
Polyester resin and CSM mat or 1708 cloth is OEM build for the greater majority of the fiberglass boats to glass over the decking and tie the deck to the hull and waterproof everything..
I notice your fuel tank is looking pretty gnarly, it will last a lot longer if you'll remove it and take it down to bare metal and repaint it.