Warren, in answer to your specific question, I used Pettit Hydrocoat for the first time last year, having previously used Interlux CSC, (both being multi-season ablatives). For a fraction of the cost, I was completely satisfied with the comparable results at season's end, (some slime, but no barnacles), and as an added bonus, the coverage with the Hydrocoat was much better, and the application easier. Additionally, fumes during application were minimal. Based on my experience on our Catalina 34, I highly recommend Hydrocoat. By the way, pressure washing the hull on haulout to remove the slime did not go through the two coats I had applied in the Spring! Hope this helps,
Cheers,
Barry
Cheers,
Barry