Abstract: A ski including a lower gliding face, bordered by ridges respectively constituting an outer edge (5) and an inner edge (4), the inner edge corresponding to the two opposite edges of two skis of a pair of skis for accommodating an intermediate device consisting of at least one platform (10, 30, 45, 60, 70, 85, 90, 91, 100) on which a safety binding, composed of a toe piece and a heel piece, is mounted, the longitudinal mid-plane (25, 66, 81, 108) of the platform being coincident with the longitudinal mid-plane (6) of the gliding board, when the device supports the skier's weight. The intermediate device includes means for shifting the position of the longitudinal mid-plane (25, 66, 81, 108) of the platform, relative to the longitudinal mid-plane (6) of the ski board and at least one return member (12, 22) for returning the two longitudinal mid-planes respectively of the platform and of the gliding board, back to the coincident position.