A signal buoy (1) for retrieval of submerged objects, the signal buoy line's cross section has an aspect ratio greater than two and two tenths to one and preferably greater than four to one. In some aspect the signal buoy line includes conductors so as to permit communicating with submerged objects. In other aspects, the present disclosure teaches a combination of a signal buoy and a buoyant fiber mooring rope storage structure for storing submerged in a body of water and above a seabed or other bottom of the body of water a fiber mooring rope for future retrieval.

Aquatic structures with adjustable buoyancy constructed in part with a vent valve for a buoyancy control device suitable for divers, where the vent valve may be opened by any combination of over-pressure, manual pressure relief or a powered means, where a force to a valve plug is applied by means of a spring that is constrained to prevent entirely lateral and angular movement but in which movement of the plug in the axis of the seat is unconstrained.

Aquatic structures with adjustable buoyancy constructed in part with a vent valve for a buoyancy control device suitable for divers, where the vent valve may be opened by any combination of over-pressure, manual pressure relief or a powered means, where a force to a valve plug is applied by means of a spring that is constrained to prevent entirely lateral and angular movement but in which movement of the plug in the axis of the seat is unconstrained.

The present disclosure includes an underwater retrieval device for retrieving an underwater instrument. The device includes a buoyancy means, a cable reel, a controller configured to receive an external signal, a release mechanism in communication with the controller, and a locking mechanism configured to lock the cable reel. The locking mechanism can comprise a locking pin engageable with the cable reel, a locking lever biased in an unlocked configuration, and a lock for securing the locking lever in the locked configuration. There is also provided an underwater retrieval system that includes the underwater retrieval device and a rewinder device that can rewind the device without disassembly or replacement of parts. When the device receives the external signal, the controller sends a signal to the release mechanism, which releases the lock and unlocks the cable reel, which allows the device to return to the surface via the buoyancy means.

The present disclosure includes an underwater retrieval device for retrieving an underwater instrument. The device includes a buoyancy means, a cable reel, a controller configured to receive an external signal, a release mechanism in communication with the controller, and a locking mechanism configured to lock the cable reel. The locking mechanism can comprise a locking pin engageable with the cable reel, a locking lever biased in an unlocked configuration, and a lock for securing the locking lever in the locked configuration. There is also provided an underwater retrieval system that includes the underwater retrieval device and a rewinder device that can rewind the device without disassembly or replacement of parts. When the device receives the external signal, the controller sends a signal to the release mechanism, which releases the lock and unlocks the cable reel, which allows the device to return to the surface via the buoyancy means.

A subsea system for installing, suspending and removing underwater equipment below the surface of the sea is provided. The subsea system includes a landing base module for landing and positioning underwater equipment thereupon, the landing base module comprising a base member and a first buoyancy system; and a second buoyancy system for affixing to the underwater equipment, the second buoyancy system having sufficient buoyancy to float the underwater equipment toward the surface of the sea when detached from the landing base module, wherein the underwater equipment includes a ballast system structured and arranged to permit the underwater equipment to be lowered onto the landing base module. A method for installing, suspending and removing underwater equipment below the surface of the sea and a kit of parts are also provided.

A subsea system for installing, suspending and removing underwater equipment below the surface of the sea is provided. The subsea system includes a landing base module for landing and positioning underwater equipment thereupon, the landing base module comprising a base member and a first buoyancy system; and a second buoyancy system for affixing to the underwater equipment, the second buoyancy system having sufficient buoyancy to float the underwater equipment toward the surface of the sea when detached from the landing base module, wherein the underwater equipment includes a ballast system structured and arranged to permit the underwater equipment to be lowered onto the landing base module. A method for installing, suspending and removing underwater equipment below the surface of the sea and a kit of parts are also provided.

An example safety system for underwater diving includes a biological sensor for detecting a diver in distress, an alarm system, and a rescue deployment system. The sensor detects an anomalous condition and issues an alarm, such as, for example, a buzzer or a flashing light. In another example embodiment, upon determining the existence of a major, persistent, time-critical anomaly, or upon being instructed by the diver, the system inflates the diver's buoyancy compensation device and brings her toward the surface at a controlled rate. In another example embodiment, upon determining the existence of such an anomaly, or upon being instructed by the diver, the system releases a buoy, allowing the buoy to float to the water surface and alert others. In another example embodiment, the buoy detects its position upon reaching the surface and issues a radio signal, indicating distress and its current position.

An example safety system for underwater diving includes a biological sensor for detecting a diver in distress, an alarm system, and a rescue deployment system. The sensor detects an anomalous condition and issues an alarm, such as, for example, a buzzer or a flashing light. In another example embodiment, upon determining the existence of a major, persistent, time-critical anomaly, or upon being instructed by the diver, the system inflates the diver's buoyancy compensation device and brings her toward the surface at a controlled rate. In another example embodiment, upon determining the existence of such an anomaly, or upon being instructed by the diver, the system releases a buoy, allowing the buoy to float to the water surface and alert others. In another example embodiment, the buoy detects its position upon reaching the surface and issues a radio signal, indicating distress and its current position.

A release device for releasing another device in an environment includes a housing containing a material matrix. A member is restrained by the material matrix and extends outside the housing. The matrix is a solid in conditions of the environment to hold the member stationary in opposition to predetermined force. The matrix softens at a predetermined softening temperature to permit relative movement between the member and the material matrix. A heating element is disposed to heat the material matrix to the predetermined softening temperature. A method for releasing a device includes attaching the device to a member extending out of the release device. The device remains attached against the predetermined force. The matrix is heated to the softening temperature in response to a communication to permit movement of the member to fully or partially release the device.