I have an Avon dinghy that is old (since 1992) and last summer one of the part of the floor out of wooden broke. I tried to repair it but it semmes that it is a special wood. It is 3/8'' thick and have at my eye, 7 plies. It is 27''X35''. It is rigid enough to all the weight we put in the dinghy even myself (250pounds).

What would you suggest me to replace the broke piece? kind of marine plywood?

What would be the best way to protect that piece knowing that the piece will often be in water during the summer (varnish or other composition)?

I would like to purchase something that will last for long time.

Thank you for any help