I had a few dings in the hull, (from slowly sliding onto the beach), the biggest was the size of a half dollar. I picked up a "Match N Patch", Gel Coat Repair Kit at West Marine, manufactured by Evercoat......(around $49, they also sell a smaller version for $39. but it was half the size)
The "white" still needed a little tinting to match my Seadoo white hull, but no problemo as the stuff doesn't start setting until you add the hardener...mix thoroughly and eye match...then add hardener and apply. The kit includes screed tool, mix sticks, plastic sheets to cover, and a prep / cleaning solvent...
This was my first attempt at patching a boat, the kit made it pretty easy, make sure you screed it off real tight so you won't have to sand through too much excess material. I picked up some 400 / 600 grit wet sandpaper, (not in the kit), after a fair amount of sanding and buffing and waxing it looks pretty good, I know where the repairs are but nobody else seems to notice...
Main ingredient required...confidence (plus read / follow the instructions, and work fast after you add the hardener) Good luck!