A fiberglass boat is a laminated structure consisting of layers of various reinforcing fabrics and core materials, bonded together with resin, and covered with a layer of gelcoat. Blisters occur when water penetrates the laminate and dissolves water soluble materials below the gelcoat layer. This attracts more water through the process of osmosis and pressure on the surrounding area creates gelcoat blisters. Unfortunately this mixture turns acidic which can attack the resin and damage the integrity of the hull.

On a more positive note blisters can occur which do not mean osmosis and there is often the possibility to treat the localized area rather than the whole hull should it be required.

This is where we come in to diagnose the issue and tell you the best way to proceed.