In a watercraft, an engine rotational speed sensor detects a rotational speed of an engine. A determining section determines if a prescribed execution condition indicating that a hull body is moving is satisfied. A filter processing section applies a filter process to the engine rotational speed detected by the engine speed sensor to acquire a filtered engine rotational speed. A control section executes a maximum speed limiting control to limit a maximum speed of the watercraft when the prescribed execution condition is satisfied and the filtered engine rotational speed is larger than a prescribed rotational speed threshold value.

A floating power generation system includes a marine vessel, an energy conversion system mounted on the marine vessel, and a fuel storage system mounted on the marine vessel. The energy conversion system includes a hydrogen fuel cell, and the fuel storage system is fluidly connected to the energy conversion system. The fuel storage system supplies hydrogen fuel to the hydrogen fuel cell of the energy conversion system.

A floating power generation system includes a marine vessel, an energy conversion system mounted on the marine vessel, and a fuel storage system mounted on the marine vessel. The energy conversion system includes a hydrogen fuel cell, and the fuel storage system is fluidly connected to the energy conversion system. The fuel storage system supplies hydrogen fuel to the hydrogen fuel cell of the energy conversion system.

A modular watercraft is disclosed which includes plural connectable modules and which can be broken down for ease of handling, transport and storage. The watercraft includes novel means for connecting separate modules. The connectable modules may be storable within a single one of the modules.

Disclosed is a marine fuel cell-based integrated heat, electricity, and cooling supply system comprising a power supply system and a waste heat recovery system; the power supply system comprises wind turbine generator sets, solar generator sets, and a fuel cell power module; the waste heat recovery system encompasses a turbine power generation module and a lithium bromide refrigeration module; the fuel cell power module is connected to both the turbine power generation module and the lithium bromide refrigeration module; the turbine power generation module is used to generate electricity using waste heat. This approach fully exploits the waste heat from the exhaust gas generated by the fuel cell power module, resulting in a high overall energy utilization rate. The self-consumption electricity and pure hydrogen fuel for the integrated energy supply system can be obtained from solar and wind energy, ensuring low carbon emissions for the entire system.

A watercraft including a hull; a deck; a propulsion system to propel the watercraft; an electric motor to drive the propulsion system; a battery; and at least one heat exchanger at least partially extending out of the hull such that at least a portion of the heat exchanger is in contact with the body of water, a first cooling circuit in thermal communication with the heat exchanger and at least one of the battery and the electric motor, the first cooling circuit being configured to circulate a heat exchange fluid therein, a second cooling circuit being in thermal communication with an other one of the at least one of the electric motor and the battery, the second cooling circuit being in fluid communication with the body of water during operation of the watercraft for circulating water from the body of water in the second cooling circuit during use.

A fuel conducting device for conducting a fuel includes: a line which includes a core line and an encasement space surrounding the core line, the core line being configured for conducting the fuel, the encasement space being configured for being filled with a liquid encasement space medium; and a conveyor device which is fluidically connected with the encasement space, the conveyor device being configured for conveying the liquid encasement space medium into the encasement space.

A fuel conducting device for conducting a fuel includes: a line which includes a core line and an encasement space surrounding the core line, the core line being configured for conducting the fuel, the encasement space being configured for being filled with a liquid encasement space medium; and a conveyor device which is fluidically connected with the encasement space, the conveyor device being configured for conveying the liquid encasement space medium into the encasement space.

An electric marine propulsion system for a marine vessel is provided. The system includes a power storage system, an electric motor powered by the power storage system and configured to rotate a propulsor to propel the marine vessel, and a control system. The control system is configured to operate the electric motor according to an operator demand signal, determine whether at least one filter latch condition is satisfied, and responsive to a determination that the at least one filter latch condition is satisfied, operate the electric motor according to a filtered motor input.

A fuel cell ship includes a propulsion device that generates propulsive force on a hull by electric power, an electric power supply unit that supplies the electric power to the propulsion device, and a degradation rate control unit that adjusts a degradation rate. The electric power supply unit includes a plurality of fuel cells that generate electric power by an electrochemical reaction of fuel and at least one storage battery.