Mine had a 6" fracture when I bought it,. I chased it , glassed it and gelcoated it, seems to be solid so far. It was right behind the rear beam, 6" down.. It was easy to sand and add a layer of glass on the inside through the access port. I got lucky. There was no structural member there.

My 5.0 had a 6" fracture in front of the main beam. right at the top of the long. struct member. same fix. single layer glass hulls so I just fixed from the outside.