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.

An amphibious robot is provided. An aspect of the robot includes an elongated flexible body, actuators in the flexible body and spaced apart along a length of the flexible body. The actuators are configured to move the flexible body in a serpentine or concertina motion on land and in water. An additional aspect includes a camera coupled adjacent to an end of the flexible body, at least one sensor coupled to the flexible body, and a buoyancy controller located in the flexible body. Another aspect includes a power source coupled to the flexible body and configured to power the actuators, the camera, the sensors, and the buoyancy controller. Yet another aspect employs an electric controller to control the actuators and receive data from the sensors.

An amphibious robot is provided. An aspect of the robot includes an elongated flexible body, actuators in the flexible body and spaced apart along a length of the flexible body. The actuators are configured to move the flexible body in a serpentine or concertina motion on land and in water. An additional aspect includes a camera coupled adjacent to an end of the flexible body, at least one sensor coupled to the flexible body, and a buoyancy controller located in the flexible body. Another aspect includes a power source coupled to the flexible body and configured to power the actuators, the camera, the sensors, and the buoyancy controller. Yet another aspect employs an electric controller to control the actuators and receive data from the sensors.

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 system includes a controller configured or programmed to perform a control to rotate a hull by driving an auxiliary propulsion device having a maximum output smaller than a maximum output of a main propulsion device and having a steering angle range wider than a steering angle range of the main propulsion device without generating a thrust from the main propulsion device.

The present disclosure is directed towards a power distribution system for a marine vessel. The power distribution system comprises auxiliary, first and second buses and first and second propulsors for propelling the marine vessel. A first power generation system is electrically connected to the first bus and operably connected to the first propulsor. A second power generation system is electrically connected to the second bus and operably connected to the second propulsor. The first and second buses are electrically connected to the auxiliary bus such that electrical power is transferable between the first and second power generation systems for driving the first and/or second propulsors.

The present disclosure is directed towards a power distribution system for a marine vessel. The power distribution system comprises auxiliary, first and second buses and first and second propulsors for propelling the marine vessel. A first power generation system is electrically connected to the first bus and operably connected to the first propulsor. A second power generation system is electrically connected to the second bus and operably connected to the second propulsor. The first and second buses are electrically connected to the auxiliary bus such that electrical power is transferable between the first and second power generation systems for driving the first and/or second propulsors.

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 device for moving a fluid with magnetic gear includes two first balls each having a shape of sphere, respectively fixed to a rotating first shaft through respective centers of the sphere, each of the first balls having a first magnetic dipole in a direction orthogonal to the first shaft; and a second ball having a shape of sphere attaching a blade structure thereon to move the fluid, fixed to a freely rotatable second shaft through a center of the sphere, and having a second magnetic dipole in a direction orthogonal to the second shaft, wherein the centers of the first and second balls altogether form an isosceles triangle with a vertex angle being defined about the center of the second ball, satisfying $=2\arcsin \left(\frac{1}{\sqrt{3}}\right)70.53.$

A device for moving a fluid with magnetic gear includes two first balls each having a shape of sphere, respectively fixed to a rotating first shaft through respective centers of the sphere, each of the first balls having a first magnetic dipole in a direction orthogonal to the first shaft; and a second ball having a shape of sphere attaching a blade structure thereon to move the fluid, fixed to a freely rotatable second shaft through a center of the sphere, and having a second magnetic dipole in a direction orthogonal to the second shaft, wherein the centers of the first and second balls altogether form an isosceles triangle with a vertex angle being defined about the center of the second ball, satisfying $=2\arcsin \left(\frac{1}{\sqrt{3}}\right)70.53.$