The “bladder” of a BCD, or Buoyancy Control Device, is an inflatable chamber designed to regulate a diver’s buoyancy. Positioned on the back of the BCD, it connects to the scuba tank through a low-pressure inflator hose.

When the diver adds air to the BCD bladder, either orally or by pressing a button connected to the regulator, the bladder fills with air, increasing the BCD’s volume. This makes the diver more buoyant, causing them to ascend in the water. Conversely, releasing air from the bladder, achieved by using the deflator mechanism, reduces the BCD’s volume, making the diver less buoyant and facilitating descent or achieving neutral buoyancy at a specific depth.

In summary, the BCD bladder is a vital component, enabling divers to control their buoyancy effectively for a safe and comfortable underwater experience.