Metal scraper will probably dig into the gel coat. If it's not too late to save it, use a plastic scraper. I would try to find some type of solvent to cut the adhesive if a heat gun won't loosen it. Looks like one of those jobs that will take a lot of time and patience. Similar to when I had to strip layers of paint
off our vintage teardrop, inside and out. Took me a few months, little section at a time. EDIT; I used a air powered die grinder with the 2" scotch discs, but they would probably damage the gel coat unless you're real careful.