Abstract: A water ski binding includes: a flexible rear boot member for the rear part of the foot of the skier; a rear mounting structure for the boot member having wall surface structure which rises generally upwardly with respect to the top surface of the ski; and another rear mounting structure for the boot member, also having wall surface structure which rises generally upwardly with respect to the top surface of the ski, which slides relative to the first mounting structure in order to press the boot member between such wall surface structures and mount the boot member on the ski. The second mounting structure is formed to support the heel of the skier and the flexible boot member is formed to be held in position substantially solely through abutting wall surfaces of the mounting structures and boot member.