A weight distribution system configured to be integral with a boat or with its structure or hull. The system includes a weight distribution device that translates a cart of weight from one position within a space to another position along a rail. The system is activated by a control that is remote to the system. The system allows for a person to quickly and conveniently alter the weight within the boat to alter, improve or otherwise shape the wake created by the boat.

A weight distribution system configured to be integral with a boat or with its structure or hull. The system includes a weight distribution device that translates a cart of weight from one position within a space to another position along a rail. The system is activated by a control that is remote to the system. The system allows for a person to quickly and conveniently alter the weight within the boat to alter, improve or otherwise shape the wake created by the boat.

A seabased resupply system includes a fuel containment structure containing fuel and extending fore and aft along a longitudinal axis, a pump on the fuel containment structure operable to pump the fuel, containers located on an exterior of opposite lateral sides of the fuel containment structure, and an operating system located inside one or more of the containers, the operating system comprising at least one selected from a power supply, a communication system, and a control processor.

A passive heave compensator comprising: a main hydraulic cylinder, including a moveable piston having a piston rod extendible through the main hydraulic cylinder and a piston head, a gas phase above the piston head, and at least one oil phase below the piston head separated by a boundary; an upper connection point associated with the main hydraulic cylinder and a lower connection point associated with the piston rod; and at least one accumulator, the or each accumulator having a moveable separator to divide the accumulator between a gas phase above the separator, and an oil phase below the separator, and the or each oil phase being in communication with an oil phase in the main hydraulic cylinder; characterized in that the main hydraulic cylinder further comprises a cylinder sleeve co-axial with the piston head to provide, in co-ordination with the piston head, the boundary between the gas phase and the at least one oil phase in the main hydraulic cylinder. In this way, the variation in the coordination between the shape, longitudinal position, or both of the piston head, which naturally must be smaller in cross-section than the cross-section of the main hydraulic cylinder, and the transverse extent of the cylinder sleeve, provides variation in the cross-sectional area of oil volume in the main hydraulic cylinder, and thus different damping effects along the length of the main hydraulic cylinder, which are available to the user.

A passive heave compensator comprising: a main hydraulic cylinder, including a moveable piston having a piston rod extendible through the main hydraulic cylinder and a piston head, a gas phase above the piston head, and at least one oil phase below the piston head separated by a boundary; an upper connection point associated with the main hydraulic cylinder and a lower connection point associated with the piston rod; and at least one accumulator, the or each accumulator having a moveable separator to divide the accumulator between a gas phase above the separator, and an oil phase below the separator, and the or each oil phase being in communication with an oil phase in the main hydraulic cylinder; characterized in that the main hydraulic cylinder further comprises a cylinder sleeve co-axial with the piston head to provide, in co-ordination with the piston head, the boundary between the gas phase and the at least one oil phase in the main hydraulic cylinder. In this way, the variation in the coordination between the shape, longitudinal position, or both of the piston head, which naturally must be smaller in cross-section than the cross-section of the main hydraulic cylinder, and the transverse extent of the cylinder sleeve, provides variation in the cross-sectional area of oil volume in the main hydraulic cylinder, and thus different damping effects along the length of the main hydraulic cylinder, which are available to the user.

A jet propulsion watercraft includes a vessel body, an engine, a jet propulsion unit, a weight information obtaining processor, an engine controller, and a target rotational speed determining processor. The engine is accommodated in the vessel body. The jet propulsion unit is driven by the engine and propels the vessel body. The weight information obtaining processor obtains weight information regarding a weight of the vessel body. The engine controller controls an engine rotational speed such that a vessel velocity reaches a predetermined set velocity. The target rotational speed determining processor determines a target engine rotational speed corresponding to the set velocity in accordance with the weight information. The engine controller controls the engine rotational speed such that the vessel velocity reaches the set velocity based on the target engine rotational speed determined in accordance with the weight information.

A jet propulsion watercraft includes a vessel body, an engine, a jet propulsion unit, a weight information obtaining processor, an engine controller, and a target rotational speed determining processor. The engine is accommodated in the vessel body. The jet propulsion unit is driven by the engine and propels the vessel body. The weight information obtaining processor obtains weight information regarding a weight of the vessel body. The engine controller controls an engine rotational speed such that a vessel velocity reaches a predetermined set velocity. The target rotational speed determining processor determines a target engine rotational speed corresponding to the set velocity in accordance with the weight information. The engine controller controls the engine rotational speed such that the vessel velocity reaches the set velocity based on the target engine rotational speed determined in accordance with the weight information.

A floating structure in the form of a spar which from a base (12) includes a first ballast weight (16), an entrapped fluid compartment (18), an equipment compartment (20), a second ballast weight (22) and a topside (24) wherein, in use, the structure floats with the water line between the topside and the second ballast weight. The arrangement utilises vertical spacing between physical masses and entrapped fluid to increase the natural period in pitch and roll motions to provide high stability. Embodiments of entrapped fluid compartments are described. The floating structure finds application in hydrocarbon recovery in shallow water and offshore renewables.

A floating structure in the form of a spar which from a base (12) includes a first ballast weight (16), an entrapped fluid compartment (18), an equipment compartment (20), a second ballast weight (22) and a topside (24) wherein, in use, the structure floats with the water line between the topside and the second ballast weight. The arrangement utilises vertical spacing between physical masses and entrapped fluid to increase the natural period in pitch and roll motions to provide high stability. Embodiments of entrapped fluid compartments are described. The floating structure finds application in hydrocarbon recovery in shallow water and offshore renewables.

A method of controlling a turbine of a floating wind turbine structure to reduce fatigue of moorings of the floating wind turbine structure includes curtailing the turbine based on a pitching motion of the floating wind turbine structure and on a wind direction at the floating wind turbine structure relative to an orientation of the moorings of the floating wind turbine structure. Optionally, the curtailment may be further based on a degree of displacement of the floating wind turbine structure from a reference location.