repairing wet wood filled fiberglass.

My floor has been flexing on my boat when i run in choppy water and I've been told it's bc my floor most likely is holding some water in it, which makes sense bc I see some small amounts of water leaking out where the previous owner mounted their transducer. And I also see water seeping up where my console meets the floor. My deck and bow have both been rotted out and replaced so now I'm sure my floor and or transom are next. I've heard of ppl using some sort of resin or epoxy that you can fill you boat with after you've drained it out. Has anyone tried this before? And if so how did you drain it? I feel like the only proper way to treat rotten wood is with a saw, but this is an older boat and I'm not trying to go upside down in this thing. Besides the floor flexing in choppy water it is still very strong, zero flat spots on my boat and the transom is holding up strong. It's a 14ft poling skiff btw with a 50hp Evinrude on the back. Also has a newer gel coat job done about 8 months ago. I have plent of pics I can post if anyone is curious about the layout.