There are two common styles of BCDs available today. Both operate in the same manner, but differ in the location of the air bladder.

Jacket BCDs are the most popular style. With this style, the bladder wraps around both sides of the body. This style is popular because it helps maintain a vertical position while resting at the surface. However, when fully inflated, some jacket style BCDs may squeeze the diver.

With back inflation or rear buoyancy BCDs, the entire bladder is located behind the diver. This means that no matter how much air is in the bladder, the BCD fits and feels the same. However, with this style maintaining a vertical position while at the surface may be more difficult.