Buoyancy Compensators. The buoyancy compensator device or BCD for short, is primarily used to help the diver maintain neutral buoyancy underwater during the scuba dive.
Three main purposes for using a BC. The first is to be able to float (maintain positive buoyancy) at the surface before and after your dive. The second is to allow you to fine tune your buoyancy underwater during your dive. The third, and most overlooked purpose to using a BC is to secure your tank to your body.
Styles of BC’s you will have to choose from: Jacket Style BC, Back-Inflate BC, and Sidemount BC.