Gyro-controlled pitch stabilizing system

Apparatus for reducing pitching motion of a moving vessel driven by one or more screws in the stern of the vessel, comprising:

• a hull adapted to float on the surface and to be at least predominantly buoyantly supported at all operating speeds and be subjected to pitching action from surface waves, the hull having a stern portion that normally extends below the at-rest even-keel load waterline, stabilizing fin means extending across the stern of the hull substantially the full beam width of the hull, means secured to the stern of the hull and the fin means for rotatably supporting the fin means at the stern of the hull, said means supporting the fin means being anchored to the hull at positions adjacent the outboard ends of the fin means and providing rotation of the fin means about a substantially horizontal axis transverse to the vessel, the fin means being positioned aft of the screws, drive means rotating the fin means about the axis of the hinge means to change the angle of attack of the fin means as it moves through the water, and means sensing changes in the pitch of the vessel for actuating the drive means to reduce the pitching motion of the hull.