An underwater actuator includes: a housing to be immersed under water; a cylinder chamber formed in the housing; a piston accommodated in the cylinder chamber so the piston is movable in a sliding manner in the cylinder chamber, the piston dividing the cylinder chamber into a first and a second pressure receiving chambers; a rod extending from the piston to the first pressure receiving chamber side, the rod penetrating the housing; a release chamber formed in the housing, having an internal pressure kept lower than a water pressure outside of the housing; and a switching mechanism including: a first switcher configured to switch a communication state between the second pressure receiving chamber and the outside of the housing to allow or block communication therebetween; and a second switcher configured to switch a communication state between the second pressure receiving chamber and the release chamber to allow or block communication therebetween.

Certain aspects of the present disclosure generally relate to cleaning geophysical equipment in water. An exemplary method includes illuminating, with laser light, an obstruction on the geophysical equipment while the geophysical equipment is deployed in an operable configuration (e.g., towed by a survey vessel).

A coupling device for recovering an unmanned ship includes: a coupling unit, which is lifted and lowered by being connected to a crane provided in a mother ship; an accommodation unit provided in the unmanned ship, and having a vertically communicating coupling hole; a guide unit performing guiding such that the coupling unit is coupled to the accommodation unit, and including a towing line formed to be long, and a winch connected to the other side of the towing line so as to selectively wind or unwind the towing line; and a control unit including a sensing part for sensing the tension applied to the towing line by the driving of the winch, and a control part for lowering the coupling unit connected to the crane, if the intensity of the tension sensed by the sensing part is a preset value or higher.

A system is designed to increase diver safety in a high-risk environment containing one or more hazardous materials. The system includes chemically-hardened surface-supplied diving equipment designed to provide full environment isolation for the diver. The system also includes a dive helmet and a surface-return exhaust system, where the surface-return exhaust system includes a demand exhaust regulator that serves as a pressure-actuated valve to enable exhausting to a breathable atmosphere outside of a dive helmet instead of exhausting into the environment containing one or more hazardous materials. The system also includes retrofittable kits enabling the upgrading of contaminant-vulnerable materials of an existing dive helmet. The system also includes fluoroelastomeric materials and components to implement in a closed circuit dive system.

A system is designed to increase diver safety in a high-risk environment containing one or more hazardous materials. The system includes chemically-hardened surface-supplied diving equipment designed to provide full environment isolation for the diver. The system also includes a dive helmet and a surface-return exhaust system, where the surface-return exhaust system includes a demand exhaust regulator that serves as a pressure-actuated valve to enable exhausting to a breathable atmosphere outside of a dive helmet instead of exhausting into the environment containing one or more hazardous materials. The system also includes retrofittable kits enabling the upgrading of contaminant-vulnerable materials of an existing dive helmet. The system also includes fluoroelastomeric materials and components to implement in a closed circuit dive system.

An aquatic vessel basically includes a floating body, a submersible propulsion unit and a communication device. The floating body has an above water level surface and a below water level surface. The submersible propulsion unit is disposed on the floating body beneath the below water level surface of the floating body. The communication device is disposed on the floating body above the above water level surface of the floating body. The communication device is wired to the submersible propulsion unit, and is configured to wirelessly communicate with a control module.

An aquatic jet propulsion device basically includes a portable main control module, a plurality of submersible propulsion units and a sub-two-way communication device. The portable main control module includes a main controller and a main two-way communication device. Each of the submersible propulsion units includes a motor, a battery electrically connected to the motor and a motor controller operatively connected to the motor to control a speed of the motor. The sub-two-way communication device is configured to communicate with the main two-way communication device. The main controller is programmed to individually control the speed of the motors of the submersible propulsion units via the motor controllers.

An aquatic jet propulsion device basically includes a portable main control module, a plurality of submersible propulsion units and a sub-two-way communication device. The portable main control module includes a main controller and a main two-way communication device. Each of the submersible propulsion units includes a motor, a battery electrically connected to the motor and a motor controller operatively connected to the motor to control a speed of the motor. The sub-two-way communication device is configured to communicate with the main two-way communication device. The main controller is programmed to individually control the speed of the motors of the submersible propulsion units via the motor controllers.

An underwater data center includes an electronic device; a housing member that houses the electronic device and that is configured to be disposed under water; and a heat exchanger that is provided at the housing member and that is configured to discharge, into the water, heat discharged from the electronic device, with a face of the heat exchanger that discharges the heat making contact with the water, an opening being formed in a bottom face of the housing member and placing an inside of the housing member in communication with the water.

An apparatus, system and method for removing and treating contaminated materials on a bottom of a body of water and introducing growth packets to revitalize the treated bottom of the body of water. The structure may comprise a vessel with an open face. The vessel may be lowered down to the bottom of the body of water with the face facing down. As a result, the vessel and the bottom form an isolated space. The structure may comprise at least one agitating device(s) for stirring up the materials inside the vessel so as to form a mixture containing the sediment materials which in turn contain the contaminants. Multiple at least one pipe(s) may be coupled to the vessel for transporting the mixture out of the vessel for processing (filtering, treating with chemicals, etc.) so as to neutralize or eliminate the contaminants in the mixture. Then, the treated mixture can be returned to the inside of the vessel via the at least one pipe(s).