A separable buoy includes a center float, a separable float unit that is detachably furnished in the center float and a chamber which is connected between the center float and the separable float unit.

An underwater object retrieval device for selective deployment to retrieve underwater objects includes an inflation unit that is configured to inflate upon command. A coupler is configured for coupling to an object to be placed underwater. A tether line has a first end, which is coupled to the inflation unit, and a second end, which is coupled to the coupler. A line storage unit is coupled to the tether line proximate to the second end. The line storage unit is positioned to house the tether line, such that the tether line is extensible from the line storage unit. The inflation unit is positioned to inflate upon user directed command, such that the inflation unit is buoyant. The tether line is extended from the line storage unit, such that the inflation unit reaches the water surface. The tether line is configured for retrieving the object to the surface.

An untethered device includes a tool and a ballast weight. The ballast weight includes an attachment plate that is securable to the tool, a dissolvable ballast, and attachment elements that secure the dissolvable ballast to the attachment plate. At least one of the attachment elements is dissolvable to release the dissolvable ballast from the attachment plate.

An untethered device includes a tool and a ballast weight. The ballast weight includes an attachment plate that is securable to the tool, a dissolvable ballast, and attachment elements that secure the dissolvable ballast to the attachment plate. At least one of the attachment elements is dissolvable to release the dissolvable ballast from the attachment plate.

An untethered device includes a tool and a ballast weight. The ballast weight includes an attachment plate that is securable to the tool, a dissolvable ballast, and attachment elements that secure the dissolvable ballast to the attachment plate. At least one of the attachment elements is dissolvable to release the dissolvable ballast from the attachment plate.

An untethered device includes a tool and a ballast weight. The ballast weight includes an attachment plate that is securable to the tool, a dissolvable ballast, and attachment elements that secure the dissolvable ballast to the attachment plate. At least one of the attachment elements is dissolvable to release the dissolvable ballast from the attachment plate.

A shot gun flotation device includes an inflatable arrangement comprising a water sensitive mechanism; an inflatable bladder; and a source of gas for inflating the inflatable element. Housing has a first tubular section attached to the shot gun, a tubular transition section, and a second tubular section for housing the inflatable arrangement. A further embodiment comprises an attachment adapter, a frame, and a sheath. The attachment adapter includes a first end section with threads for attachment to the shot gun, a middle section for mounting a ring, and a second end section with external threads for engaging the frame. The frame supports an inflatable arrangement and a sheath houses the inflatable arrangement and the frame when in an inoperative state. Further embodiments include an inflatable arrangement with a bladder stored in housing and a CO.sub.2 cartridge for inflating the bladder when the inflatable arrangement is activated.

A shot gun flotation device includes an inflatable arrangement comprising a water sensitive mechanism; an inflatable bladder; and a source of gas for inflating the inflatable element. Housing has a first tubular section attached to the shot gun, a tubular transition section, and a second tubular section for housing the inflatable arrangement. A further embodiment comprises an attachment adapter, a frame, and a sheath. The attachment adapter includes a first end section with threads for attachment to the shot gun, a middle section for mounting a ring, and a second end section with external threads for engaging the frame. The frame supports an inflatable arrangement and a sheath houses the inflatable arrangement and the frame when in an inoperative state. Further embodiments include an inflatable arrangement with a bladder stored in housing and a CO.sub.2 cartridge for inflating the bladder when the inflatable arrangement is activated.

A fishing trap retrieval system comprising a strong rope adapted for being connected to a fishing trap at a first end thereof. A strong rope buoy is connected to a second end of the strong rope. A mid portion of the strong rope is maintained in a collapsed form. A load sensitive release mechanism is connected to the strong rope buoy and adapted for being connected to the fishing trap. A weak rope is connected to the release mechanism at a first end thereof and to a surface buoy at a second end thereof. The release mechanism is adapted for transferring a buoyancy load exerted by the strong rope buoy when submerged to the fishing trap in a first mode of operation and for releasing the strong rope buoy when the load acting thereon exceeds a predetermined load threshold in a second mode of operation.

A subsea structure monitoring system can include a base device configured to be secured to a subsea structure. The subsea structure monitoring system can also include a release mechanism disposed within the base device, where the release mechanism has a default state and a released state. The subsea structure monitoring system can further include a buoy detachably coupled to the release mechanism, where the buoy includes a housing that houses a communication module and a switch. The subsea structure monitoring system can also include a trigger that is configured to convert the release mechanism from the default state to the released state. The release mechanism can be converted from the default state to the released state when the trigger exerts a minimum force on the release mechanism.