Abstract: An improvement to a wave ski comprising an adjustable seat which slides longitudinally along a track located on the upper surface of the wave ski and a fin associated with the seat, whereby the user can simultaneously adjust the longitudinal position of the seat by the use of footrests and the fin on the wave ski. In another embodiment of the invention, the adjustable seat which moves longitudinally along a track located on the upper surface of the wave ski and the fin associated with the seat includes a slot extending longitudinally along or adjacent to the center line of the wave ski and is adapted to receive the fin or portion of the seat, whereby the user can again simultaneously adjust the longitudinal position of the seat and fin on the wave ski.