Jackets
 
The jackets are known as Bouyancy Control Devices or BCD for short. A BCD is an expandable bladder that the diver inflates or deflates to regulate his or her buoyancy. This can be done orally, using air from the diver's lungs, but most of the time a low pressure inflator is used. It inflates the BCD with air directly from the diver's oxygen tank. To decrease buoyancy, the BCD is deflated through a hose or valve.
The BCD also provides positive buoyancy for resting, swimming or lending assistance to others. BCDs are considered standard equipment mandatory for scuba diving.
Here are a few examples of BCDs :
 
Contour BC by Oceanic
Contour BC by Oceanic
OceanPro 5K by Oceanic
OceanPro 5K by Oceanic
 
for more information on BCDs, please visit these sites :
Oceanic
Mares