Methods of protecting a propeller include applying an inner polymer layer onto a propeller. The inner polymer layer is impregnated with a biologically active chemical substance that inhibits biofouling-induced chemical, biological, and bio-proliferative damage and that does not chemically or galvanically interact with a material of the propeller. An outer polymer layer is applied onto the inner polymer layer, the outer polymer layer being impregnated with a biologically active chemical substance that inhibits biofouling-induced chemical, biological, and bio-proliferative damage and that repels biofouling organisms to prevent invasion of the inner polymer layer.