Could be air in the lay up but more than likely a dodgy spray job as grp needs different prep to steel.
The gel coat needs to be really "killed with 80 grit pad on a da"" to get rid of any wax as this attacks the paint, star cracks should be dug right out as will just come back to haunt you even after rubbing down and the appear to have gone....spooky stuff grp but not as spooky as wiring