Aspects of the present disclosure are directed to a method of refueling an electric watercraft. The method may include detecting, by one or more sensors, an unlock signal as a function of unlocking a first battery pack from a first receiver, receiving, by a computing device, the unlock signal, and disabling, by the computing device, the first battery pack and a second battery pack simultaneously, in response to receiving the unlock signal. Disabling the first battery pack and the second battery pack may further include disabling the first battery pack using a first contactor and the second battery pack using a second contactor. Aspects of the present disclosure may also be direct to a system for refueling an electric watercraft.

A cooling system for marine jet engines includes a marine jet engine assembly, a pressurized raw water inlet, a centrifugal filter, a strainer, and a hull-mounted heat exchanger. The marine jet engine assembly is configured with an engine, a drive shaft, a stator, a manifold heat exchanger, an exhaust, a water pump, and a coolant outlet so that the vessel can be functional. The pressurized raw water intake is in fluid communication with the stator. The centrifugal filter is in fluid communication with the pressurized raw water intake to supply a direct flow of raw water from the stator. The raw water is then cleaned through the strainer, discharged into a water inlet of the manifold heat exchanger, and discharged from a water outlet of the manifold heat exchanger before exiting into the exhaust. The hull-mounted heat exchanger is in fluid communication with the coolant outlet and the water pump.

A fuel control system (300) for fuel consumption calculation for a fuel and water mixture is provided. The fuel control system (300) includes a mixer (330), a fuel source (310) fluidly coupled to the mixer (330), the fuel source (310) being configured to measure a flow of fuel to the mixer (330), a water source (315) fluidly coupled to the mixer (330), the water source (315) being configured to measure a flow of water to the mixer (330), and a mixture flow meter (5) fluidly coupled to the mixer (330). The mixture flow meter (5) is configured to receive and measure properties of a fuel/water mixture from the mixer (330).

A drive for a boat includes a housing that is arranged underwater during operation, and that houses an electric motor that drives a propeller. The housing includes a cooling section that includes a coolant duct.

A method of operating a heat exchanger involves conveying a first fluid having a first temperature along spaced apart first passages of the heat exchanger and conveying a second fluid along spaced apart second passages of the heat exchanger while the first fluid is being conveyed along the first passages to transfer heat from the second fluid to the first fluid. The method also includes conveying a fluid along the third passages when the temperature of the second fluid in at least some of the second passages is below a predetermined temperature to transfer heat from the fluid being conveyed along the third passages to the second fluid.

A method of operating a heat exchanger involves conveying a first fluid having a first temperature along spaced apart first passages of the heat exchanger and conveying a second fluid along spaced apart second passages of the heat exchanger while the first fluid is being conveyed along the first passages to transfer heat from the second fluid to the first fluid. The method also includes conveying a fluid along the third passages when the temperature of the second fluid in at least some of the second passages is below a predetermined temperature to transfer heat from the fluid being conveyed along the third passages to the second fluid.

The invention relates to a pod propulsion device including a motor casing (3) and a strut (2), which strut (2) is connected at a lower part thereof to the motor casing (3) and is arranged to be connected at an upper part thereof to a hull (1) of a ship. The motor casing (3) includes a housing (6) enclosing an electric motor (5) with a stator and a rotor, which housing (6) has an upper portion. According to the invention a stationary heat conducting means (7) is arranged in contact with said upper portion, which heat conducting means (7) is arranged to conductively connect the upper portion to at least one outer wall (21) of the strut (2). The invention also relates to a ship provided with such pod propulsion device and to a method for cooling a pod propulsion device.

The invention relates to a pod propulsion device including a motor casing (3) and a strut (2), which strut (2) is connected at a lower part thereof to the motor casing (3) and is arranged to be connected at an upper part thereof to a hull (1) of a ship. The motor casing (3) includes a housing (6) enclosing an electric motor (5) with a stator and a rotor, which housing (6) has an upper portion. According to the invention a stationary heat conducting means (7) is arranged in contact with said upper portion, which heat conducting means (7) is arranged to conductively connect the upper portion to at least one outer wall (21) of the strut (2). The invention also relates to a ship provided with such pod propulsion device and to a method for cooling a pod propulsion device.

The present disclosure provides an apparatus for transferring a liquid cargo. The apparatus for transferring a liquid cargo according to an embodiment of the inventive concept may include a liquid cargo transfer line connected to a liquid cargo storage tank, a drum connected to the liquid cargo transfer line and providing a space for storing a liquid cargo, and a pressing unit for pressing the liquid cargo storage tank so that the liquid cargo stored in the liquid cargo storage tank is supplied to the drum through the liquid cargo transfer line.

The present disclosure provides an apparatus for transferring a liquid cargo. The apparatus for transferring a liquid cargo according to an embodiment of the inventive concept may include a liquid cargo transfer line connected to a liquid cargo storage tank, a drum connected to the liquid cargo transfer line and providing a space for storing a liquid cargo, and a pressing unit for pressing the liquid cargo storage tank so that the liquid cargo stored in the liquid cargo storage tank is supplied to the drum through the liquid cargo transfer line.