I bought a 1985 Ozark Tri Hull. I have not been around boats for 25 years so I'm new to this. I took it out three times and found out the transom is rotten in the center section. I was going to try and take the deck off so I could replace the transom but the front is glassed to the hull and I have no way to get in and cut it loose. I'm thinking about Sea cast for the Transom. Sounds like it will do what I need. The only thing is I have no way to check the stringers. The floor seems solid with no movement. Would it work to put some pour able foam in the cavities just in case something is wrong with the stringers?