Controlled buoyant lift

The controlled buoyant lift is an underwater diver rescue technique used by scuba divers to safely raise an incapacitated diver to the surface from depth. It is the primary technique for rescuing an unconscious diver from the bottom. It can also be used where the distressed diver has lost or damaged his or her diving mask and cannot safely ascend without help, though in this case the assisted diver would normally be able to control their own buoyancy.

The standard PADI-trained technique is for the rescuer to approach the face-down unconscious diver (victim) from above and kneel with one knee either side of his or her diving cylinder. Then, with the victim's diving regulator held in place, the tank is gripped firmly between the knees and the rescuer's buoyancy compensator is used to control a slow ascent to the surface.

In the technique taught by BSAC, the rescuer faces the casualty and uses the casualty's buoyancy compensator to provide buoyancy for both divers as the rescuer makes a controlled ascent. If the casualty is not breathing, the ascent will be urgent. If the two divers separate during the ascent, the use of the casualty's buoyancy is intended as a failsafe causing the casualty to continue to the surface where there is air and other rescuers can help.