A watercraft comprising a battery ballast system is shown and described. The battery ballast system comprises a plurality of carriage assemblies, each comprising a plurality of tiers along the watercraft's height axis, and each being movable along the watercraft's length axis. The batteries sit on movable supports that are movable along the watercraft's width axis. Each tier is loaded to less than 50 percent with batteries and battery supports so that the batteries in each tier can be moved along the ship's width axis relative to the hull in a manner that will affect the ship's list. The carriage assemblies occupy a portion of the length along which they are movable so that they can be moved along the ship's length axis relative to the hull to affect the ship's trim. In certain examples, the ship's potable water system is used to change the watercraft's total amount of ballast by changing the total volume of treated water on board such as by expelling treated water overboard or changing the rate of untreated water being fed to the potable water system.

A watercraft comprising a battery ballast system is shown and described. The battery ballast system comprises a plurality of carriage assemblies, each comprising a plurality of tiers along the watercraft's height axis, and each being movable along the watercraft's length axis. The batteries sit on movable supports that are movable along the watercraft's width axis. Each tier is loaded to less than 50 percent with batteries and battery supports so that the batteries in each tier can be moved along the ship's width axis relative to the hull in a manner that will affect the ship's list. The carriage assemblies occupy a portion of the length along which they are movable so that they can be moved along the ship's length axis relative to the hull to affect the ship's trim. In certain examples, the ship's potable water system is used to change the watercraft's total amount of ballast by changing the total volume of treated water on board such as by expelling treated water overboard or changing the rate of untreated water being fed to the potable water system.

A marine propulsion unit includes a stern drive mounted to a transom. The stern drive comprises an upper unit enclosed in a stern drive housing and a lower unit enclosed in a gearbox housing; wherein the gearbox housing contains a gearbox arranged to drive at least one propeller. The propulsion unit further comprises at least two electric motors arranged in the stern drive housing, which electric motors are mounted with vertical output shafts; a planetary gear set arranged between the at least two electric motors and the gearbox, and a vertical shaft that is attached to a ring gear of the planetary gear set at its upper end and is connected to the gearbox at its lower end; wherein the output shaft of each electric motor is connected to a planetary gear arranged in the planetary gear set to drive the ring gear and the vertical shaft connected to the gearbox.

A marine propulsion unit includes a stern drive mounted to a transom. The stern drive comprises an upper unit enclosed in a stern drive housing and a lower unit enclosed in a gearbox housing; wherein the gearbox housing contains a gearbox arranged to drive at least one propeller. The propulsion unit further comprises at least two electric motors arranged in the stern drive housing, which electric motors are mounted with vertical output shafts; a planetary gear set arranged between the at least two electric motors and the gearbox, and a vertical shaft that is attached to a ring gear of the planetary gear set at its upper end and is connected to the gearbox at its lower end; wherein the output shaft of each electric motor is connected to a planetary gear arranged in the planetary gear set to drive the ring gear and the vertical shaft connected to the gearbox.

A motor comprising: (a) a stator having a plurality of ferrous cores surrounded by a plurality of windings; (b) a pair of rotors positioned on opposing sides of the stator, each rotor including a ring gear; and (c) a drive shaft extending through a cutout of the stator, the drive shaft having a pinion gear positioned near an end of the drive shaft in communication with the ring gears of the rotors; wherein the rotors rotate in opposing directions so that the ring gears translate a movement of the rotors to the drive shaft through the pinion gear to rotate the drive shaft in a direction substantially orthogonal to a direction of rotation of the rotors.

A motor comprising: (a) a stator having a plurality of ferrous cores surrounded by a plurality of windings; (b) a pair of rotors positioned on opposing sides of the stator, each rotor including a ring gear; and (c) a drive shaft extending through a cutout of the stator, the drive shaft having a pinion gear positioned near an end of the drive shaft in communication with the ring gears of the rotors; wherein the rotors rotate in opposing directions so that the ring gears translate a movement of the rotors to the drive shaft through the pinion gear to rotate the drive shaft in a direction substantially orthogonal to a direction of rotation of the rotors.

A personal watercraft is disclosed including a flotation portion, a strut extending from the flotation portion, and a motor pod is disposed along the strut with an electric motor operably coupled to a driveshaft. A hydrojet unit is removably attached to the motor pod and includes an inlet portion removably attached to the motor pod and a substantially cylindrical housing. The inlet portion includes a substantially conical motor interface with a shaft through-hole for receiving the driveshaft therein, one or more fins extending outwardly from the conical motor interface, and at least one ring encircling the conical motor interface and connecting to each of the one or more fins for inhibiting objects from passing through the inlet region. The housing defines a fluid flow path to an outlet portion. The hydrojet unit includes an impeller coupled to the driveshaft and a stator disposed within the housing.

A personal watercraft is disclosed including a flotation portion, a strut extending from the flotation portion, and a motor pod is disposed along the strut with an electric motor operably coupled to a driveshaft. A hydrojet unit is removably attached to the motor pod and includes an inlet portion removably attached to the motor pod and a substantially cylindrical housing. The inlet portion includes a substantially conical motor interface with a shaft through-hole for receiving the driveshaft therein, one or more fins extending outwardly from the conical motor interface, and at least one ring encircling the conical motor interface and connecting to each of the one or more fins for inhibiting objects from passing through the inlet region. The housing defines a fluid flow path to an outlet portion. The hydrojet unit includes an impeller coupled to the driveshaft and a stator disposed within the housing.

A mobile offshore drilling unit includes a plurality of electric thrusters to dynamically position the drilling unit, and a microgrid electric power generation system for providing power to the plurality of electric thrusters, the microgrid electric power generation system including at least one combustion generator electrically coupled to a main electric power bus and at least one thruster electric power system, the thruster electric power system including a thruster electric power bus, an additional electric power bus connected to the thruster electric power bus via an interface device, and a circuit breaker electrically coupling the additional electric power bus to a main electric power bus for isolating the thruster electric power bus from the main electric power bus in case of loss of power on the main electric power bus.

A mobile offshore drilling unit includes a plurality of electric thrusters to dynamically position the drilling unit, and a microgrid electric power generation system for providing power to the plurality of electric thrusters, the microgrid electric power generation system including at least one combustion generator electrically coupled to a main electric power bus and at least one thruster electric power system, the thruster electric power system including a thruster electric power bus, an additional electric power bus connected to the thruster electric power bus via an interface device, and a circuit breaker electrically coupling the additional electric power bus to a main electric power bus for isolating the thruster electric power bus from the main electric power bus in case of loss of power on the main electric power bus.