Abstract: A watercraft performance type device for facilitating the on-plane operation of a watercraft comprising a plate-like member which is specifically designed to be removably attachable to the underside portion of the cavitation plate associated with the lower drive unit of a typical outboard motor or stern drive assembly, the plate-like member including an angularly related tab portion extending downwardly substantially across the rear end portion thereof, an opening strategically positioned for receiving the downwardly extending torque tab commonly associated with most cavitation plates, the torque tab opening being located and dimensioned so as to enable the torque tab to extend therethrough when the plate-like member is attached in operative position to the underside portion of the cavitation plate, and a cut-out arrangement associated with the front end portion of the plate-like member for positioning and locating the same in close abutting relationship with that portion of the lower drive unit located adjac