Easy Off Oven Cleaner and a plastic pot scrubber.
Spray on the cleaner and let it sit for 10-15 mins. The pot scrubber will help break up the paint (small circular motion). Wipe off with paper towels- don't wet the area until you are ready for a final rinse. Be careful not to let the stuff run down on any stripes or other paint. If the paint is real thick you may have to repeat the process a couple times.
If it discolors the gelcoat (sometimes turns it a yellowish tint)- put some bleach on a rag and wipe it.
Here's a job in progress.