An unloading type sinking rescue device of a subsea mining vehicle and a use method thereof are provided. The unloading type sinking rescue device includes an assembly support, an unloading system, an ejection system and a control system. The assembly support is box-shaped, fixed to a subsea mining vehicle, and provided with a plurality of enclosed cavities. The unloading system includes a counterweight, a counterweight cable, a counterweight fixing bracket and a counterweight recovery cavity. The ejection system includes an anchor, an ejection cavity, an anchor cable, an anchor recovery shaft, a pulley, a spring and a boosting device. The control system controls the operation of the unloading system and the ejection system. The use method includes: (1) unloading; (2) ejection; (3) recovery of a part of counterweights; (4) recovery of the anchor; and (5) recovery of remaining counterweights.

An apparatus for creating on-command buoyancy is provided with an elastically deformable and axially elongated watertight hollow shell having a plurality of leaf springs and enveloped by a flexible skin. When flattened, the shell has a small internal volume and is negatively buoyant. The hollow shell is held in this position by a latch mechanism. When the mechanism is released, the leaf springs expand to increase the internal volume of the shell. In this state, the system is buoyant. A release mechanism for the latch bar is provided in a forward closure to permit transition from negatively buoyant to a buoyant configuration when an external signal is received.

An apparatus for creating on-command buoyancy is provided with an elastically deformable and axially elongated watertight hollow shell having a plurality of leaf springs and enveloped by a flexible skin. When flattened, the shell has a small internal volume and is negatively buoyant. The hollow shell is held in this position by a latch mechanism. When the mechanism is released, the leaf springs expand to increase the internal volume of the shell. In this state, the system is buoyant. A release mechanism for the latch bar is provided in a forward closure to permit transition from negatively buoyant to a buoyant configuration when an external signal is received.

An apparatus (10) for lifting and moving an object that is underwater. The apparatus including a first (12) and a second (14) chamber, both chambers containing a first (16) and a second (18) fluid. There is a conduit (20, 21) in fluid communication with the first and second chambers, the first and second fluids moveable between the first and second chambers.