Last 3 years using Rustoleum on sailboat prop prior to that Pettit for many years. Barnacles depend on the year here in the Chesapeake. Some years with Pettit, I had lots of barnacles, some very little. In the last 3 with Rustoleum, 1 year none, 2 years with minimal. One comment was Pettit is harder. I think that is correct and to me who likes to start fresh each year, that was a draw back. The Rustoleum is easier to remove. This year I used 3 coats (instead of 2) on bare bronze prop and still too cold to dive and check.