A ski for a snowmobile is provided with a pair of lateral wings and a central channel for increasing the flow of snow under a gliding surface at the bottom of the ski. The increased flow of snow enhances flotation of the ski. The channel may be formed by two downwardly extending keels. The wings are defined between the keels and outer edges of the ski. The keels may be asymmetric with a shorter keel being positioned toward an outer edge of the snowmobile to improve handling characteristics of a snowmobile.