In 2009 I bought a 2006 Vista 278 which had bottom paint on it. I moved the boat to a dry stacker and seriously considered removing the old antifouling and applying primer and topcoat paint below the waterline. After I couple of years and before making a decision I moved to a wet pen (salt water) and I'm back to maintaining anti-fouling paint.
For a boat that is stored out of the water, new gelcoat would be cost prohibitive but the best option might be to remove the old bottom paint, prepare the surface, prime and topcoat paint.
A two pack spray job by a professional would be the answer but a cheaper option would be a DIY paint job with rollers and brushes.
I had the blue fibreglass stripe on my boat painted - if I was going to switch back to dry storage I would go back to the same painter have the bottom of the hull cleaned off and painted.
