Old thread or no, still a good topic. How long your zincs last varies tremendously and the OP was off base in blaming Gori for his lack of maintenance. We can go about one year on the zincs on the sailboat but the zincs on the outdrive on the crab boat need to be replaced about every four months and the little zinc on the Autoprop on our last sailboat was gone in about six months. It's just common sense to check the zincs every couple of months on a different prop or in a new marina.
SV Laurie Anne
1988 Brewer 40 Pilothouse