According to an embodiment of the present disclosure, a vessel includes: a hull 100 provided with a propellant 140; a deck 200 spaced apart from the hull 100; and a support 300 between the hull 100 and the deck 200, the support 300 configured to support 300 the deck 200 with respect to the hull 100, wherein the hull 100 is disposed below a water surface during operation, and the deck 200 is supported by the support 300 to be disposed above the water surface during operation.

A suspension system for a vessel (1) having at least one left hull (11), at least one right hull (12) and a chassis portion (10), the suspension system including supports (20) for at least partially supporting the chassis portion relative to the left and right hulls, and a front left and back left damping ram (31, 33) connected between the chassis portion and longitudinally spaced points on the at least one left hull, a front right and back right damping ram (32, 34) connected between the chassis portion and longitudinally spaced points on the at least one right hull. The suspension system further includes a deck attitude control system (250) comprising a controller (252), sensors, and a respective actuator arrangement for each of at least two orthogonally spaced damper rams. The actuators control a position of at least one point on the chassis relative to at least one reference.

A stabilizer (10) includes a base (20) fixed on a motion reduction target (1); a gimbal (40) supported by the base to be rotatable around a first axis (RA); a damper mechanism (30) disposed to damp a relative rotary motion of the gimbal (40) to the base (20); a flywheel (50) disposed to be rotatable around a second axis (RB) orthogonal to the first axis (RA). The damper mechanism (30) is a passive-type damper mechanism. A first value (D1) of a damping coefficient (D) of the damper mechanism (30) when an angular velocity of the gimbal (40) is a first angular velocity is larger than a second value (D2) of the damping coefficient (D) of the damper mechanism (30) when the angular velocity of the gimbal (40) is a second angular velocity smaller than the first angular velocity.

A method of manufacturing marine riser buoyancy elements includes providing a master mold and mold inserts such that a range of buoyancy elements may be manufactured from one master mold and providing the mold inserts such that an annular space between the riser main conduit and the buoyancy elements, or a groove width between the buoyancy elements may be varied during manufacture.

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.

Aspects of the present disclosure relates to disruptive coupling systems and methods, and apparatus thereof, for subsea systems. The subsea systems may be subsea oil and gas systems. In one implementation, a subsea system includes a subsea component disposed in seawater, and a disruptive coupling device coupled to the subsea structure and/or surrounding fluid.

A method and structure for mooring seaworthy craft against boat landings is disclosed. The structure comprises a fender (4) with a layer of compressible material having an exposed surface, mounted on the craft. Anchor points (12) are secured at laterally spaced locations on the craft, as are two draw mechanisms (14), one associated with each anchor point (12). A tie (10) is provided for extending from each anchor point (12) to its associated draw mechanism (14), and each mechanism is operable to draw its respective tie from an anchor point around a pylon thereby urging the fender (4) against both pylons. In the mooring process, the craft is first steered to the boat landing to engage the fender (4) against the pylons (6), and the ties (10) are withdrawn from each draw mechanism (14) and taken around one of the pylons. Each tie is then attached to an anchor point (12) on the craft, and the mechanisms (14) are activated to draw the ties (10) around the pylons to urge the fender (4) against them. A control system maintains the required tension in the ties to secure the mooring.

A porous-structure device includes a semi-submersible platform consisting of four columns, two pontoons, two horizontal supports and a deck. Fillets on middle portions of the columns have a square section, a radius of the fillets, close to the deck and the pontoons, of the columns is gradually decreased to 0, a porous device is disposed outside each column and is formed by combining and connecting four single components, and each single component is formed by combining and connecting a plurality of porous laminated plates and a plurality of connecting pieces. The parameters, such as the pore type, porosity, number of layers, interlayer spacing and installation height, of the porous laminated plates are set according to the wave characteristics in different sea areas.

A system for countering the rolling motion of a marine vessel, includes one or more sensors adapted to characterize a sea condition approaching the vessel, one or more control systems, a computer, and one or more active stabilizers. The computer is adapted to receive the characterized sea condition data, is further adapted to generate one or more control signals in dependence on the characterized sea condition data, and is still further adapted to transmit the or each control signal to the or each control system. The or each control system is in turn adapted to actuate the or each active stabilizer in response to receipt of the or each control signal, to counter the rolling motion of the marine vessel.

A floating offshore wind power generation facility includes a floating body, a mooring cable, a tower, and a windmill installed at the top of the tower, the windmill including a nacelle and a plurality of blades. The rotation axis of the windmill has a predetermined upward angle to avoid contact between the blades and the tower, and the windmill is of a downwind type in which the blades are attached to the leeward side of the nacelle and installed with the back surfaces of the blades facing windward, and the mooring point of the mooring cable to the floating body is set at a position below the surface of the sea and higher than the center of gravity of the floating body.