BCDs

The BCD or buoyancy compensator device manages a diver's buoyancy by counteracting weights worn, that assist in decent. They also allow for adjusting for neutral buoyancy at depth. An individual's buoyancy varies primarily with salt vs fresh water and wetsuit thickness. Common features for most BC’s include: adjustable shoulder and waist straps, quick release shoulders for easy removal, rear trim weight pockets to balance the diver while moving in the water or at the surface, releaseable weights, and an auto-inflator that uses pressurized scuba tank air to positively pressurize the air cell.  Considerations for choosing a BCD include comfort, fit, number of D-rings, warranty, and basic quality of the material used.