If it was painted with urethane (Brightsides?), many urethanes such as Awlgrip, Imron, etc. are not repairable, so you'd have to paint the whole thing. Other urethanes, such as Awlcraft,
Signature Finish and the EMC Quantum stuff sold by forum member Shine can be touched up, wet sanded/buffed and repaired, so much more practical for a boat that you're actually gonna use! Gel coat will require about same or more labor, but with only 3-6 month durability between waxing compared to YEARS for the urethanes! Gel coat might be cheaper, but I wouldn't even consider it for doing entire boat!