A power transmission device transmits power underwater to a power reception device including a power reception coil. The power transmission device includes: a power transmission coil that transmits power to the power reception coil through a magnetic field; a power transmitter that transmits an alternating current power having a predetermined frequency to the power transmission coil; and a first capacitor that is connected to the power transmission coil and forms a resonance circuit resonating with the power transmission coil. The predetermined frequency is a frequency between a first frequency at which a geometric mean value of a Q value of the power transmission coil and a Q value of the power reception coil are the maximum and a second frequency at which the Q value of the power transmission coil and the Q value of the power reception coil are the same.

A charging system for an autonomous underwater vehicle includes: a sea floating body; a charging station suspended in water from the body through a string-shaped body and located downstream of the sea floating body by receiving a water flow, the station including a noncontact electricity supplying portion located away from the string-shaped body; and an autonomous underwater vehicle coupled to the station that is rotatable about the string-shaped body, the vehicle including a noncontact electricity receiving portion configured to receive electricity supplied from the supplying portion, wherein: the station takes by the water flow such a posture that the noncontact electricity supplying portion is located downstream of the string-shaped body in a water flow direction; and when the vehicle is coupled to the station, the vehicle takes by the water flow such a posture that the receiving portion is located downstream of the string-shaped body in the water flow direction.

A charging system for an autonomous underwater vehicle includes: a sea floating body; a charging station suspended in water from the body through a string-shaped body and located downstream of the sea floating body by receiving a water flow, the station including a noncontact electricity supplying portion located away from the string-shaped body; and an autonomous underwater vehicle coupled to the station that is rotatable about the string-shaped body, the vehicle including a noncontact electricity receiving portion configured to receive electricity supplied from the supplying portion, wherein: the station takes by the water flow such a posture that the noncontact electricity supplying portion is located downstream of the string-shaped body in a water flow direction; and when the vehicle is coupled to the station, the vehicle takes by the water flow such a posture that the receiving portion is located downstream of the string-shaped body in the water flow direction.

A submarine support ship is preferably a triple-hulled vessel; the lower portion of the ship is a paired-hull catamaran which is capable of deep diving, clasping the submarine at deep sea, and floating upwards together with the clasped submarine. The upper portion of the ship is a buoyancy tank, which can supply air to and pull up the deep-diving lower portion, and can also conduct security of an ocean-going submarine. For the submarine support ship of the present invention, by utilizing a mature deep diving submersible technology, the lower portion of the submarine support ship is manufactured as a deep-diving submersible in a submarine contour form, which is quickly separated from the upper portion of the submarine support ship and dives to reach the submarine position in the deep sea, clasps the submarine and then floats upwards together with the submarine as a whole to the water-surface position, such that the egress hatch of the submarine is docked with a dedicated docking hatch of the submarine support ship, to implement rescue security of the submarine; which mainly solves the problem that the rescue water-depth of current deep-diving lifeboats is shallow, but it also solves the problems that the deep-diving lifeboat has many rescue links, slow speed, and can only save people, but not submarines.

An apparatus for use with a submerged compartment is presented. The apparatus includes deployable physical connection hardware provided with the submerged compartment. The deployable physical connection allows for a transfer of fluid between the submerged compartment and a region near a marine free surface when deployed. The deployable physical connection hardware comprises a hose in one aspect.

An apparatus for use with a submerged compartment is presented. The apparatus includes deployable physical connection hardware provided with the submerged compartment. The deployable physical connection allows for a transfer of fluid between the submerged compartment and a region near a marine free surface when deployed. The deployable physical connection hardware comprises a hose in one aspect.

Systems and methods for deployment and retrieval of ocean bottom seismic receivers. In some embodiments, the system includes a carrier containing receivers. The carrier can include a frame having a mounted structure (e.g., a movable carousel, movable conveyor, fixed parallel rails, or a barrel) for seating and releasing the receivers (e.g., axially stacked). The structure can facilitate delivering receivers to a discharge port on the frame. The system can include a discharge mechanism for removing receivers from the carrier. In some embodiments, the method includes loading a carrier with receivers, transporting the carrier from a surface vessel to a position adjacent the seabed, and using an ROV to remove receivers from the carrier and place the receivers on the seabed. In some embodiments, an ROV adjacent the seabed engages a deployment line that guides receivers from the vessel down to the ROV for on-time delivery and placement on the seabed.

Systems and methods for deployment and retrieval of ocean bottom seismic receivers. In some embodiments, the system includes a carrier containing receivers. The carrier can include a frame having a mounted structure (e.g., a movable carousel, movable conveyor, fixed parallel rails, or a barrel) for seating and releasing the receivers (e.g., axially stacked). The structure can facilitate delivering receivers to a discharge port on the frame. The system can include a discharge mechanism for removing receivers from the carrier. In some embodiments, the method includes loading a carrier with receivers, transporting the carrier from a surface vessel to a position adjacent the seabed, and using an ROV to remove receivers from the carrier and place the receivers on the seabed. In some embodiments, an ROV adjacent the seabed engages a deployment line that guides receivers from the vessel down to the ROV for on-time delivery and placement on the seabed.

A modular underwater lighting apparatus includes an outer housing, a supporting mount, and a plurality of lighting devices. The outer housing includes an outer surrounding wall extending to surround a longitudinal axis and made of a light-transmissive material. The supporting mount is mounted inside the outer housing. The lighting devices are separately mounted on the supporting mount. Each of the lighting devices includes a circuit component and a lighting module which is detachably mounted to the circuit component.

In an oscillating fin propulsion apparatus adapted for use by a disabled diver, a propulsion force may be produced by a fin adapted to sweep back and forth in a generally transverse direction relative to the traveling direction of the diver. The fin may be mounted on a scuba tank operatively connected to drive members that may be reciprocated by the diver. The oscillating fin may provide a propulsive force propelling the diver forward during both oscillating directions of the fin.