Are you trying to strip the Gelcoat?
If not, keep at it! it took 2 months to sand the Deck, Cockpit, Topsides, Hull, and Keels of a 20 foot bilge keel yacht.
I learnt a lesson about stripper - ensure you throughly wash it off with water after it has done it's job. Another bit of advice for paint stripper - cover it over with clingfilm. It should make it easier!