[macojoe]

Well if its that rotted I don't think that stuff is going to work.

From under in the cabin, you will have to take a drill with a 1/4 bit and drill a few hole (not all the way thur) to see were you have good wood.

Bad wood will be like dirt, good wood will be clean.

After ou find how far around the cleat is rotted you can draw a square around and cut it out. This will leave the top skin in place.

Now take one or two 3/4 ply and coat it with resin to water proof it. screw cleat into the new wood, this will hold the wood in place, then you can reglass the bottom to the top and you good to go.

Thats what I would do.