I've got an old yamaha jetski from the late 80's that I decide to tear down for the winter. I've got more money into the thing that its worth already, so I figured since I'm going to keep it, I may as well fix it up. Engine is apart for a rebuild/overbore, jet pump is rebuilt, and the hull is stripped and upside down in my garage. I/m planning on just brushing on some new gelcoat to spruce it up and make it smooth again. The bottom is quite scratched and dinged up. The plan is to sand it down as smooth as possible which I can do to eliminate most of the scratches, but I need some suggestions as to what should be done to the major dents/dings to smooth them out before I repaint?