I have tried all kinds of restorer wax. 3M, Cullinite, Mequirs et al. Some last 2 months and some last for the season. I always end up 'restoring' it again next year. Have a pro examine your boat. He will tell you if you need a good buffing, wet sanding or a repaint/gelcoat. Paint/gelcoat is very thin. You don't want to end up sanding it off.
I had a 20 year old Liberator that came out great using an orbital sander and rubbing compound. It was sored in doors in the winter and moored in a shady area. The current boat also 20 years old, was another story. It was stored outdoors and the slip was in a sunny area. It was heavily oxidized and wet sanding sanded the paint off. I have new paint and it looks great!
Give Diamond Shine a call. I value his opinion.
There is another way to cover a boat. It is like using a huge plastic material that covers the side of the boat. You can even had graphic to it. The company 'prints' the sheets on a printer. They have a five year warrantee on the product. It is a lot cheaper than paint.
http://www.racelinedigital.com/