I have a 73 hallmark 21 footer. My boat seems to be really heavy and the floor is starting to rot. There are a couple of spots that need to be replaced. I also have a problem with a low transom so I was thinking that if it was saturated and I had to tear up the floor how much would all of this cost to make a higher transom and redo the floor. Is it possible that the foam in the floor is filled with water sorta like a sponge. Thanks for any info. And what kind of work is involved seek pro or Do myself project.