A controller is configured or programmed to obtain at least either of a pitch angle of a watercraft and an angular velocity of the pitch angle, obtain a present thrust of an outboard motor, and set a target thrust of the outboard motor based on the present thrust of the outboard motor and at least either of the pitch angle of the watercraft and the angular velocity of the pitch angle. The controller is configured or programmed to control a drive source such that a thrust of the outboard motor becomes the target thrust.

A control system for posture control tabs of a marine vessel assists operations of a steering control. The posture control tabs are mounted on a stern of a hull to move up or down to control a posture of the hull. Actuators actuate the respective posture control tabs. When a steering instruction is provided through the steering control, a processor determines the posture control tab to be actuated and controls the actuator corresponding to the posture control tab determined to be actuated so as to change the position of the determined posture control tab.

Methods of, and apparatuses for, controlling at least one trim tab of a marine vessel are disclosed.

A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. For smaller units, the bearing cooling system is effective to enable a flywheel with a moment of inertia less than 11.7 kg.m.sup.2 (40000 lbm in.sup.2) to be accelerated at a rate of 5 rpm/s or greater. For larger units, the bearing cooling system is effective to enable a flywheel with a moment of inertia greater than 11.7 kg.m.sup.2 (40000 lbm in.sup.2) to be accelerated at a rate of 2.5 rpm/s or greater.

An unmanned underwater vehicle having one, some, or all of an integrated communication control fin, a ballast and trim control, a reusable trigger mechanism for a drop weight, and a visual hull display. Furthermore, associated methods are also provided.

A boat includes a propulsion device that generates, by driving of an engine, a propulsive force to propel a boat body, a trim changer that changes a trim angle of the boat body, a trim actuator that drives the trim changer, and a controller configured or programmed to control operation of the trim actuator based on a value corresponding to a change in a boat speed.

A method of monitoring accelerations on a vessel includes measuring acceleration on the vessel using one or more sensors. The one or more sensors are communicatively coupled to a computing unit. Real-time acceleration information representative of an acceleration on the vessel based at least in part on the measured acceleration from the one or more sensors is generated. Acceleration prediction information representative of predicted wave slam using the computing unit is generated. Using the acceleration prediction information, automatic control of trim, steering, or throttle controls of the vessel is performed in a fashion computed to reduce the effects of the predicted wave slam.

A system for controlling a marine vessel comprises an input device for inputting an operator command, a sensor which senses and signals an engine function variable or a vessel dynamic variable, and a first structural element and a second structural element. The first structural element and the second structural element each control speed or direction of motion of the marine vessel, and the first structural element and the second structural element each affect the marine vessel dynamic variable. There is a controller which receives the operator command and the engine function variable or the vessel dynamic variable. The controller moves the first structural element and the second structural element based on the engine function variable or the vessel dynamic variable, after receiving the single operator command.

An unmanned, autonomous, ocean-going vessel including a primary hull and a rigid wing rotationally coupled with the primary hull that freely rotates about a rotational axis. At least one of the primary hull and the rigid wing includes at least one selectively floodable compartment configured to selectively flood to submerge the primary hull and at least a portion of the rigid wing. The vessel further includes at least one controller configured to maintain a desired heading. The vessel further includes a control surface element configured to aerodynamically control a wing angle of the rigid wing based on a force exerted by wind on the control surface element. The vessel further includes a rudder. The at least one controller is further configured to determine a rudder position and generate a signal to position the rudder. The vessel further includes a keel coupled with the primary hull.

A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. The bearing cooling system enables heat generated by the bearings to be transferred through the flywheel shaft to a heat sink disposed within a cavity in the end of the flywheel shaft, or to a liquid coolant circulating within the cavity.