How important is it to go all the way to the gel coat before putting on bottom paint? It looks like there were only two prior coats. It came off with a sanding block in different layers and unfortunately I used a power washer that also made it a little uneven. I talked with an amatuer who refinishes his own boat and he said the primary job is to sand off the ridges (make smooth transitions) and then make sure the paint is high quality and consider two plus layers. The boat will be kept in the water in a salt water environment. I will be only day/coastal sailing but hopefully use it several times a month.