Delamination!!! I feel for you. I made the mistake of using polyester on an 18 ft cedar strip canoe. (it was cheap, I was stupid) The hull started to delaminate after 3 years. The first approach was to remove the delam' area and patch. The delaminated area just got bigger and bigger as we tried to find solid glass on wood. The result was total removal, and re-glass the canoe with EPOXY this time.

If you can patch with epoxy...go for it! Hope you don't run into what I did.