Abstract: A water ski also adapted for walking on land is disclosed. The ski comprises a pontoon of generally streamlined shape, formed of a lightweight rigid material, and a plurality of spaced cups of a flexible material attached to the lower surface of the pontoon, each of the cups being open at the rear end thereof to form a pocket to receive water and provide water resistance against the backward movement of the pontoon, the cups closing against the lower surface of the ponton by the action of the water during the forward motion of the pontoon to reduce drag. According to one embodiment, a plurality of fins are disposed longitudinally along its lower front portion of the pontoon and extending below the cups in the closed position thereof, and an additional fin or runner is disposed longitudinally along the lower rear portion of the pontoon and extending below the cups in the closed position thereof.