I have kept my boats in Norwalk harbor for almost 30 years. I am aware of the growth issues...However when the Sewer Treatment plant in So Norwalk overflows and dumps raw sewage into the river, you REALLY get some nutrients going into the water. But back to Prop Koat....I think I will try it this year. I have had very poor results with Prop Speed. Do you Blast your running gear each year then use Prop Koats primer and top coats? Looks like they recomend 2-3 top coats.