Thermal spray coating presents a sacrificial-anode cathodic protection method since differences between the potentials of materials are employed. If a base metal is exposed to seawater, due to defect in the thermal spray coating, the metal is protected by the sacrificial anodic characteristics of the coating layer because micro-cells formed by the base metal and the thermal spray coating act as cathodes and anodes, respectively. The coating thickness has little effect on the surface morphology of the coating. However, the electrochemical properties with the increasing of coating thickness present good results.