Pear Shaped Zinc Anode is ideal for Small to medium craft and its most common purpose is for mounting on the rudder to give complete protection. The Zinc anodes you use on a vessel are called “Sacrificial Anodes.” Zinc is used because it has a higher voltage in the water so the current will be more inclined to flow from it than from your propeller. To complete the electrical circuit, the zincs must be connected to the items they are intended to protect. Sacrificial anodes should be fitted and correctly bonded to all boats / vessels to help prevent corrosion by cathodic protection when in the water.