Contact Lavro in Monroe, WA. The original manufacturer is always the best contact and source of information. Chances are they will recommend re-glassing the bottom with a layer or two of polyester mat and then gel-cote. I would suggest you let them do the work unless you have a lot of experience, tools and a dry work place that you don't mind covering with fiberglas dust. Do a yellow pages search on Lavro and if you cannot find them let me know- I'm about 15 miles from their factory. By the way I own an aluminum Thor-built so I'm not pushing glass boats.