My wife helped me wet sand ours (1000grit). It was a repo unit and had been neglected, to say the least. At 38" long, that was a lot of wet sanding and wheeling!
I second the recommendation of Meguiar's M6332 Flagship Premium Marine Wax. Our unit is black gelcoat, this product is the best we have tried.
As for graphics ours were so badly faded and curled from the sun, I peeled them all off. If they were still on, I would not hesitate to wax right over them with the Meguiar's.
http://www.amazon.com/gp/product/B0007TR47G?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00