Unmanned underwater vehicle and system for the maintenance and inspection of underwater facilities and method of managing a tether to supply power and to control said underwater vehicle

An unmanned underwater vehicle configured to maintain and inspect a permanent underwater installation, the unmanned underwater vehicle comprising:

• a frame;
• a plurality of motorized thrusters directable to navigate in a body of water;
• a tether configured to supply power to and send control signals to the unmanned underwater vehicle from a remote location;
• and
• a tether management device configured to selectively wind and unwind the tether on board the unmanned underwater vehicle.

An underwater facility maintenance and inspection system comprising:

• an unmanned underwater vehicle comprising:
• a frame,
• a plurality of motorized thrusters directable to navigate in a body of water;
• a tether configured to supply power to and send control signals to the unmanned underwater vehicle from a remote location, and
• a tether management device configured to selectively wind and unwind the tether on board the unmanned underwater vehicle;
• and
• an underwater resident station selectively couplable with the unmanned underwater vehicle.

A method of managing a tether of an unmanned underwater vehicle, the method comprising:

• moving the unmanned underwater vehicle into a body of water, the unmanned underwater vehicle comprising a frame, a plurality of motorized thrusters directable to navigate in the body of water, the tether configured to supply power to and send control signals to the unmanned underwater vehicle, and a tether management device;
• controlling the path of the unmanned underwater vehicle from a remote station;
• unwinding the tether from the unmanned underwater vehicle along a first path;
• and
• laying the tether on a bed of the body of water.