Is there a paint remover for fiberglass?
Harsh chemicals damage the fiberglass so most chemical paint strippers for fiberglass are mild and therefore not very effective. Personally I use a thungsten carbide tipped scraper for the bulk of the work and then finish with wet and dry sandpaper. Remember fiberglass is an irritant so wear a mask, antifoul paint on fiberglass is toxic so wrap up well and keep the area you are sanding well wetted down for dust control. Some thungsten tipped scrapers come with an attachment for a vaccume cleaner which is wise when scraping antifoul.