I have a 16' fiberglass that the floor was really soft in. I took out all the seat and sure enough the wood was soggy. I cut around the edge and pulled all of it up. The foam was like the stuff they package tv's in just cut to the shape and wrapped in plastic so all of them are in good shape. Now the center board all the way down is gone so il replace it. What i was thinking was getting some plywood coating a couple times with some varnish. I was gonna put some holes where the seat bolts come up but this time use a strip of metal between the 2 bolts to make them stronger when the seats are back in place. Now i saw someone say something about the fiberglass stuff you find on bathroom walls that sell in sheets, I would use that glue it down and just fiberglass the edges. Then i will glue some of that turf looking carpet ontop of that and put the seats back in. Is there any objections to this? Im trying to keep it cheap the boat only cost me 500 and it is 40 years old.