Here is something i came across as an alternative to bottom paint:Ceram-Kote CK-99M.....is a two part Industrial epoxy coating,more UV resistant than most epoxy's,goes on fibreglass,for immersion in the marine environment...has ceramic overlapping platelets like Interprotect 2000E,( not need for a primer ).coating cures to a hard gloss coating.Also can be applied over Interprotect 2000E and can be painted.Comes in lots of different colours and lasts for many years.I guess its that coating you see over industrial machines and oil/gas pipelines.I was reading that some boaters have used it as a bottom coat and love it. Tug