Tri_X_Troll

The spot in the blue hull shown looks like, what we call, a gel coat void. Rather than a delamination. Much easier to fix. It is simply a bubble between the gelcoat and the glass. Was likely there since the boat was built. Chip away until you remove all of the gel coat around the void. Sand and fill with an epoxy filler. Sand and spray color if you want, but the filler is all you really need.