I have a 1985 Catalina 30. The boat is staying in the water this winter and I have added an extra Zinc. I purchased it from Westmarine. I've hung it over the side and ran a heavy gauge copper wire from the engine block to the steel wire for the Zinc so that the Zinc is grounded. I'm told that the backstay is also grounded and simply running the Zinc wire to the backstay would work equally as well. Any thoughts?