Dear group: When you are getting ready to place the boat back in the water this year do not forget to change those calcium-crusted zinc’s on the shaft. If the zinc’s have been on the shaft out of the water there is a potential possibility of reducing the zinc’s efficiency 100% if a oxidation has taken placed on the surface OR attaching surface of the zinc. This deposit can cause a complete isolation. Also never paint zinc OR attach zinc to a painted surface. Might as well remove the zinc in those cases. Also be aware that your engine has possibly pencil zinc’s in the manifold and possibly the oil cooler. These too should be replaced yearly. Your engine manual will have the location’s of these zinc’s outlined in the exploded view. Most pencil zinc’s are very easy to find at your local marine store. Good luck. Sincerely, Kevin L. Woody