Another vote for Pettit Zinc Coat
I think I have tried almost everything. Many different kinds of anti fouling, underwater metal primer then anti fouling, Interlux spray coating, etc.Primer and anti fouling is labor intensive to apply (lots of coats) and at the end of the season I still have barnacles and the paint is worn/chipped off so that complete removal is required. Removal is a lot of work also.The Interlux spray is not only expensive- $30, but I think it is really made out of barnacle food. Doesn't work for me.Last year I tried the Pettit Zinc coating. It worked better (not perfect, but better) than anything else I've tried. Costs is $15/can and needs two thin coats. One can will probably last me 2-3 years. This fall I had some barnacles but not as bad as other years.I'm in Narragansett Bay and conditions do vary from year to year. As they say, "Your mileage may vary..."