Abstract: Anti-roll apparatus for a marine vessel. A plurality of fins are carried by the vessel. Each fin is operatively moved by motor mechanism which is connected thereto by means of clutch mechanism. The motor mechanism is in continuous operation. A roll sensor unit is mounted in a position to detect roll motion of the vessel. The roll sensor unit transmits signals to the clutch mechanism in response to roll motion of the vessel. The clutch mechanism joins the motor mechanism to the fins for movement thereof in accordance with operation of the roll sensor unit. The fins are thus operatively moved to reduce and/or eliminate the roll action of the vessel.

Abstract: Stabilizer or anti-roll structure for marine vessels. The structure comprises a plurality of fins which are joined together as a unit, and the unit is adapted to be positioned at the side of a vessel below the water line and attached to a rotative or pivotal shaft which extends from the vessel.