The instep and the heel retaining elastomeric parts of a water ski binder are each shaped with the underside having inwardly and upwardly extending projections. Each shaped part is then secured to a separate plate having recesses to match the projections and to secure the part to the plate. The plates, with mounted parts, are then secured to a base plate; with the plate holding one of the parts longitudinally adjustably with respect to the base plate.