The following are types of BCDs.
The standard/stabilizing jacket is a “waist coat” design with air cells under the arms, in the front, at the back, and sometimes over the shoulder. This type of design has been the choice for the majority of OC divers and OC dive schools.
The design allows air to move anywhere inside the jacket. Air will gather at the highest point and thus provide very good stability. It is important to know that to release the air in the BCD, you have to hold the inflator hose higher than the BCD because of the air wanting to move higher.
Back-mount BCDs are sometimes called wings, and they have the air bladder located on the back only. There are two types of wings/bladders.
- The doughnut style has a circular bladder, allowing air all the way around. This style is preferred by recreational divers who want the clean front feel, uncluttered sides and front, and the stability of a standard jacket BCD.
- The other wing design is the horseshoe-style bladder. The design allows air to be trapped on one side to counter balance the weight that a technical diver would have while carrying stage cylinders on the side. Air movement from one side to the other is restricted and takes some time to learn to dive with. This type of bladder generally has a much larger lift capacity to accommodate for the additional weight of technical diving. It is generally not a choice for the recreational diver.
Both style of wings have oral and power inflators, and dump valves.
Some registered rebreathers are sold without a BCD or sold without a harness and wing/bladder system. If you don’t have a BCD (or the use of one) and you have not yet decided on what to purchase, then the platform harness together with a choice of bladder is a good decision to integrate into a registered rebreather. This design style can also be used to adapt to many types of technical diving. There is also a version of this design made for sidemount diving. Sidemount diving is where the cylinders are on your side, making you more streamlined for diving in wrecks and caves. You can take additional training to learn how to dive in the sidemount configuration.