A marine propulsion unit includes a duct including a stator, a propeller including a rim including a rotor disposed at a position that faces the stator and a blade provided radially inward of the rim, a steering shaft that supports the duct such that the duct is steerable, a casing provided separately from the steering shaft and that extends along a rotation axis of the propeller, and a motor controller disposed in the casing and configured or programmed to control rotational driving of the propeller.

A DC power system, having: a main bus, a plurality of power delivery devices configured to be connected to the main bus, a first zone partitioning device, and a control system, wherein the first zone partitioning device is configured to segregate the main bus into a first protection zone which is a section of the main bus to which power delivery devices with a fault clearance requirement in a first time range are configured to be connected, and a second protection zone which is a section of the main bus with a fault clearance requirement in a second time range, which includes times that are higher than any time included in the first time range, and to which no power delivery device with a fault clearance requirement in the first time range is configured to be connected, wherein the control system is configured to control the first zone partitioning device to allow load current to flow from the first protection zone to the second protection zone and to limit fault current flow from the first protection zone to the second protection zone.

A DC power system, having: a main bus, a plurality of power delivery devices configured to be connected to the main bus, a first zone partitioning device, and a control system, wherein the first zone partitioning device is configured to segregate the main bus into a first protection zone which is a section of the main bus to which power delivery devices with a fault clearance requirement in a first time range are configured to be connected, and a second protection zone which is a section of the main bus with a fault clearance requirement in a second time range, which includes times that are higher than any time included in the first time range, and to which no power delivery device with a fault clearance requirement in the first time range is configured to be connected, wherein the control system is configured to control the first zone partitioning device to allow load current to flow from the first protection zone to the second protection zone and to limit fault current flow from the first protection zone to the second protection zone.

An electrically-powered unmanned marine vehicle and method of making same, including providing a hull of the marine vehicle and mounting a submersible electric thruster to the hull via a mounting interface of the thruster. The thruster includes a stator assembly and a rotor assembly. The rotor assembly forms an internal cavity with a plurality of magnets arranged radially outwardly of the internal cavity. The stator assembly includes electrical windings that are disposed within the internal cavity of the rotor assembly. The thruster is configured to allow the internal cavity to be flooded with water when the thruster is submerged, and the electrical windings are encapsulated with a protective barrier that prevents the flooded water from contacting the windings. The thruster of the marine vehicle is thus water cooled, and the electromotive forces provided by the windings generate sufficient thrust to propel the marine vehicle through the water.

An electrically-powered unmanned marine vehicle and method of making same, including providing a hull of the marine vehicle and mounting a submersible electric thruster to the hull via a mounting interface of the thruster. The thruster includes a stator assembly and a rotor assembly. The rotor assembly forms an internal cavity with a plurality of magnets arranged radially outwardly of the internal cavity. The stator assembly includes electrical windings that are disposed within the internal cavity of the rotor assembly. The thruster is configured to allow the internal cavity to be flooded with water when the thruster is submerged, and the electrical windings are encapsulated with a protective barrier that prevents the flooded water from contacting the windings. The thruster of the marine vehicle is thus water cooled, and the electromotive forces provided by the windings generate sufficient thrust to propel the marine vehicle through the water.

A boat has a battery located within an interior of a battery-housing, which includes a waste gas outlet that has a gas-permeable seal and a pressure relief valve. The battery housing is gastight and watertight with the exception of the waste gas outlet. The gas-permeable seal is water-impermeable and comprises a semi-permeable diaphragm that allows the passage of water vapor out from the interior of the battery housing, but prevents the passage of water vapor into the interior of the battery housing.

A boat has a battery located within an interior of a battery-housing, which includes a waste gas outlet that has a gas-permeable seal and a pressure relief valve. The battery housing is gastight and watertight with the exception of the waste gas outlet. The gas-permeable seal is water-impermeable and comprises a semi-permeable diaphragm that allows the passage of water vapor out from the interior of the battery housing, but prevents the passage of water vapor into the interior of the battery housing.

Provided is a propeller for a submersible, comprising a housing (1) having a cylindrical structure with two open ends, a stator sleeve (2) having a cylindrical structure with one open end, the stator sleeve suspended in an internal cavity of the housing (1), a motor stator (3) fixed inside the stator sleeve (2), a rotor sleeve (4) having a cylindrical structure with one open end and disposed on the stator sleeve (2), a motor rotor (5) fixed to an inner wall of the rotor sleeve (4), and a propeller (6) fixed to an outer wall of the rotor sleeve (4). The propeller (6) of the underwater propeller is directly fixed to the rotor sleeve (4) so that the structure of the motor is compact, and the rotational shaft transmission is not required so that the length of the propeller is shortened and the volume is reduced.

A propulsion system for a vessel includes an engine propulsion unit that provides a propulsive force to a hull by using an engine as a power source, an electric propulsion unit that provides a propulsive force to the hull by using an electric motor as a power source, a storing mechanism that is displaced from an actuating position to actuate the electric propulsion unit to a storing position to store the electric propulsion unit and performs a storing operation to store the electric propulsion unit, and an interlock controller that interlocks a storing operation of the storing mechanism with generation of a propulsive force by the engine propulsion unit.

A propulsion system for a vessel includes an engine propulsion unit that provides a propulsive force to a hull by using an engine as a power source, an electric propulsion unit that provides a propulsive force to the hull by using an electric motor as a power source, a storing mechanism that is displaced from an actuating position to actuate the electric propulsion unit to a storing position to store the electric propulsion unit and performs a storing operation to store the electric propulsion unit, and an interlock controller that interlocks a storing operation of the storing mechanism with generation of a propulsive force by the engine propulsion unit.