You know how i hate to disagree with you mate but guess what i do,gelcoat will not hold up to the stresses caused by mounting rails on top and the stresses caused by the torque of the motor running in a boat,you only need to look at how gelcoat cracks on the outside under the stresses caused by the hulls flexing over time.No way would i trust it to hold never in a million yrs.I also wouldnt trust any hull that was gelcoated inside as id think he had something to hide?.
Mart