Any paint that is permanent and doesnt create a boundary layer of extra slipperiness, by bleeding off into the water is OK.
That said, is your gelcoat really bad? You might be surprised at how nice you can get the boat back, unless the gelcoat is cracked, crazing or really scratched up.
Do you sail in fresh or salt? Do you store the boat in the water, or on the trailer?
if stored in the water, or the gelcoat is really bad, then paint is good, otherwise, I see it as a last resort.