A torpedo recovery system is provided with a hull and a float conformable on a host vehicle and lifting wire coiled on a spool attached by an extension spring as well as with an anchor to the float. An oval hole penetrates the recovery system hull at positions lined with a watertight sleeve. The spool can accommodate a locking pin. The extension spring allows compliance for take-up of the spool by having the locking pin mate with an aperture and adds a wire pre-tension. Upon vehicle shutdown; the locking pin is retracted to free the spool from a rotational constraint. The float buoyancy translates into pulling the wire from the spool with the float and extension spring continuing to the water surface. Once the float reaches the surface; the float provides a visual location for the host vehicle. The float is retrieved and a winch can recover the lightweight torpedo.

An underwater work system of the present disclosure acquires a relative position of an underwater vehicle relative to a surface ship at the start of searching work, the relative position being measured based on a sound wave transmitted from a wave transmitter. The underwater work system calculates a position of the underwater vehicle based on the acquired relative position. When a measurement error region whose center corresponds to the calculated position of the underwater vehicle and an expected laid region of a pipeline extending in a predetermined direction overlap each other, the underwater work system moves the underwater vehicle to such a position that the measurement error region and the expected laid region do not overlap each other, and then, makes the underwater vehicle perform crossing detection in which the underwater vehicle detects the presence or absence of the pipeline while crossing the expected laid region.

A technique provides a modular sensing device having multiple separable modules attached end to end. The modules are selectable based on mission requirements, with different modules and combinations thereof selected for different mission types and/or requirements.

The invention is a system that enables passive sonar identification of underwater items by making use of lift bags and/or flags, having distinctive sequences of bands of sonar-signal-reflecting materials, wherein the lift items are partially inflated so as to present a predictable orientation with respect to the floor of a body of water and its surface.

A buoyage for emergency communication and a corresponding rescue method are provided. The buoyage for emergency communication includes: a positioning device, a buoyancy block, a plurality of compression springs, an optical fiber, a reel, a frame, an optical fiber slip ring, a pure iron disk, an optical fiber connector and an oil-filled electromagnet, wherein the positioning device is fixed on a top portion of the buoyancy block, and is configured to emit a position signal of itself when the buoyage returns to a surface of water; the buoyancy block is provided above the frame, wherein the compression springs are provided between the buoyancy block and the frame; the pure iron disk is fixedly on a center of a bottom portion of the buoyancy block. The oil-filled electromagnet is adsorbed to the pure iron disk after being energized to limit a vertical displacement of the buoyancy block.

A system for securing a submerged buoy including a signalling element floating on the surface and connected to the buoy by a link, said securing system being wherein it includes a reversible coupling device comprising an attachment member secured to the end of the link opposite the signalling element, a complementary attachment member rigidly connected to the buoy and capable of engaging with said attachment member in order to allow the link to be secured to or released from the buoy, a pressure sensor, a control unit associated with a timemeasurement unit, said control unit ordering said complementary attachment member to separate from said attachment member when a pressure variation, measured by associating said pressure sensor and said time-measurement unit, is higher than a set value.

A system for securing a submerged buoy including a signalling element floating on the surface and connected to the buoy by a link, said securing system being wherein it includes a reversible coupling device comprising an attachment member secured to the end of the link opposite the signalling element, a complementary attachment member rigidly connected to the buoy and capable of engaging with said attachment member in order to allow the link to be secured to or released from the buoy, a pressure sensor, a control unit associated with a timemeasurement unit, said control unit ordering said complementary attachment member to separate from said attachment member when a pressure variation, measured by associating said pressure sensor and said time-measurement unit, is higher than a set value.

Devices and methods for aiding a large area search for objects. A searcher transmits interrogation signals of long range relative to the return range to be received by a device at the target object. The target device responds with a ping signal modified to be more easily found by means of information contained in the interrogation signal. The information may be in the nature of the received signal or data encoded and embedded. The target device may use a microprocessor to do complex operations using the information from the interrogation signal and other information. Detection of a weak ping is facilitated by such means as being beamed in the direction of the interrogation, arriving at a predictable time, or having parameters adapted to values requested by the searcher. The object is then intercepted with help of the ping or other signals from the device.

Devices and methods for aiding a large area search for objects. A searcher transmits interrogation signals of long range relative to the return range to be received by a device at the target object. The target device responds with a ping signal modified to be more easily found by means of information contained in the interrogation signal. The information may be in the nature of the received signal or data encoded and embedded. The target device may use a microprocessor to do complex operations using the information from the interrogation signal and other information. Detection of a weak ping is facilitated by such means as being beamed in the direction of the interrogation, arriving at a predictable time, or having parameters adapted to values requested by the searcher. The object is then intercepted with help of the ping or other signals from the device.

A buoy system according to one embodiment of the present invention includes a buoy body configured to provide buoyance; a fixing belt configured to fasten the buoy body to a ship structure; an auto-release unit configured to release the buoy body to be buoyed by releasing the fixing belt when a predetermined water pressure is reached; and an auto-reel chain box fixed to the ship structure, being opened in conjunction with releasing of the fixing belt, and including a chain which is reeled out when the buoy body is buoyed, wherein the auto-reel chain box comprises: a weight provided in the auto-reel chain box and being movable upward and downward according to a water pressure and buoyance; a pulley provided in the auto-reel chain box, having the chain wounded thereon and a plurality of teeth on an outer circumferential surface thereof; and a shaft having one end connected to the weight and the other end engaging with the teeth to fix the pulley and provided to be rotatable around a portion fixed in the auto-reel chain box.