The tube is solid. The foam that came out was completely soaked. Like I could squeeze the water out of it. It’s prob a money pit but the boat floats nice even as it was holding a lot of water.
I am in the middle of a deck replacement on a 15 ft fiberglass jon boat. This boat is a hand me down and the previous owner left it in his yard partially covered. I have removed the deck to find it has no stringers(not rotten stringers). It appears the floor was supported by the rotten plywood...