I have a 22'Bayliner and recently found a blister in the fiberglass in the engine compartment. It looks like it is in a inner hull that has an approx. 3/8" of wood and then the outer main hull. This inner hull only seems to be in the rear of the boat. Can anyone tell me why this wood/inner hull is there and what is the best way to repair it? Can I remove the worst of the problem and then re-fiberglass over the hole? The main hull is fine.<br /><br />Any help you can give is much appreciated.