Abstract: An inflated roll-stabilizing keel system has a first trough-shaped bladder nd a second trough-shaped bladder attached to the underside of a forward portion of the first trough-shaped bladder. Holes pass through from the first trough-shaped bladder to the second trough-shaped bladder to allow inflation to flow therein. A plurality of shaped bladders are attached successively along and to the first trough-shaped bladder immediately aft of the second trough-shaped bladder. Each shaped bladder has a rectangular base portion attached to the underside of the first trough-shaped bladder. Each shaped bladder tapers downward from its base portion to an open apex. An inflation hole passes through from the first trough-shaped bladder to each of the shaped bladders to allow inflation air to flow therein. Once inflated, adjacent shaped bladders contact one another between the base portion and open apex in an area of contact.