I was out walking the dock in the fall and noticed a fiberglass trawler at the dock with some zinks laid out about every foot on the deck ( small screw in zinks ), Scratching my head I just walked by thinking huh must have forgotten to toss them out and just left them on the deck of the boat . Now we are into winter and they are still sitting there. I noticed that the deck of the boat had NO growth (green, black or ect) on it. Is it possible that there's something to this ?