Would help to know what the hull is made off. If wood my preferred method would be to use finishing epoxy brushed on. If you want some extra strength then a layer of lightweight glass cloth with the epoxy will do. To make it easier to sand the epoxy for the final finish then add some microballoons to slightly thicken the epoxy, these sand easier and can give a near polished finish. It's not the best idea to use polyester (car glass fibre) resin as it has a really strong and toxic smell and really needs to be used outside in the open air. Chopped strand mat and glass tissue are really intended for poyester and don't work well with epoxy.
Jim
