I've had good experience with Petits Zinc Prop and Shaft Spray. A spray paint zinc coat that is easily applied. I was so happy with a single coat last year that this Spring I put on 3 coats. Hey if a little is good, I'm hoping more is better. Anyhow, last season I experienced little barnicle growth and what was there was easily removed. Not inexpensive but less than $30 for a spray can.
Catalina 387 #29
Rock Hall, MD