A BCD (Buoyancy Control Device) is the equipment that allows a scuba diver to safely ascend and descend underwater. A built-in, expandable bladder fills with air or deflates to allow the diver to establish positive buoyancy on the surface and neutral buoyancy underwater. It is also sometimes referred to as a Buoyancy Compensator (BC) or stabilizer. BCDs are available in several styles, including jacket style, wing (back-inflate) style, and a hybrid between them.

Most BCDs incorporate an integrated weight system that also assists with managing buoyancy. Some BCDs have weight pockets, and others use a rip-cord weight system. Choose a BCD with a weight system that you are comfortable with, and make sure that the BCD’s inflator hose is compatible with your regulator.