Abstract: In the area of ships, a pair of opposing, independently operable, hydrodynamic wings deployable downward from the bottom of a marine vessel, of sufficient size and foil shape such that the low pressure created by the movement of the hydrodynamic wings through the water will control the roll, or heeling motion of the marine vessel. The extension of one wing provides the force to balance the roll to one side of the marine vessel, while the extension of the other wing provides the force to balance the roll to the other side of the marine vessel. The wings can be independently extended and retracted to any degree to provide a means of adjusting the necessary roll control force to the conditions.