Dump valves allow a diver to quickly release air from a buoyancy compensator (BC). Four standard locations for BC dump valves exist: the right shoulder, the right and left lower portions of the BC, and the inflator pull dump. Divers may also release air from the BC using the deflate button on the inflator hose, but this is not considered a dump, and is standard on all BCs.
Buoyancy compensators have dump valves in various locations to allow a diver to release air from the BC without changing his position in the water. A diver who is in a vertical position can use the right shoulder dump to vent air from the BC. A diver in a horizontal, swimming position can use a lower dump to deflate his BC. The inflator hose pull dump is operated by pulling on the BC's inflator hose, which opens a valve on the BC's left shoulder. This dump requires that the diver be in a vertical position.
When considering a buoyancy compensator, a diver should check to see that it has at least one lower dump valve. This will allow the diver to deflate the BC in a horizontal position, which he can not do with the deflate button located on the inflator hose.
