Don't paint unless you have to. If you do.....
Dark blue gelcoat gets a "greyish" look due to chalk in the pores. This can be fixed very cheaply with the Island GIrl System (for about $50-60) If the gelcoat is worn through or badly cracked etc then you could condiser painting.I would always use a two part paint in possible . I had good luck with hand application of two part interlux on the transfom, floor boards of my inflatable dinghy. You wet sant with 220 grit to keep smooth and remove runs. Use 400 grit before th last coat and (in my case) I put the last coat by spraying with a propellant system to avoid brush marks and used our masking gbel to protect the hypalon.Although I have not done it myself, the sponge roller sounds like a better idea.One last thing. It is very importatn to thoroughly wet sand (water containing detergent) and dewax the surface (use comercial wax and silicone remover from an autopaint store). before applying the paint. If you have spider cracks (see posting below) dremel them out and fill, then sand smooth. Otherwise the wax in the cracks could interfere with adhesion of the paint and cause "fisheyes".Putting some fisheye remover (actually a low viscosity silicone) in the paint is also a good idea.Remember that with dark blue, the finish has to be immaculate because of the reflective nature of this dark color.All of this means much labor - cheap if you do it yourself but expensive if you pay for it. I know I have done bodywork and paint on 4 different cars and the polyurethane pained cars came out just as good as at a shop.ThanksJim WillisThanksJim Willis