Have you looked into "Awlgrip" I used this on my P21 and I've got to say it's good stuff. This is the sort of comment it gets ............"Rumery's specializes in Awlgrip® application. Awlgrip is a high durability paint. With proper application, it is the most recommended paint in the marine environment."............ It is a bit more involved than standard 2 pack but long term, I think, it's worth it.