Rigid vinyl water jacket rub rail prevents rust from forming on stainless steel overlays. Pockets designed in the primary rub rail promote oxygen flow between the overlay and primary rub rail, which allows the backside of the insert to dry thoroughly. This design also permits a fresh water rinse between the overlay and the rub rail, virtually eliminating caustic salt deposits. Rigid vinyl rub rail tightly forms to the boat's contours. Matches gel coat finishes beautifully and has exceptional lasting qualities in the most adverse conditions.