Zinc replacement

Zinc anodes are the protection you need for your boat's metallic parts (shafts, props, rudders, etc.). These anodes are placed over and connected to the metallic parts of your boat that need protection from electrolysis-caused corrosion. Your anode should be replaced once per year as a minimum however, you should check it regularly and replace it once it has corroded to 45-50% of its original size.