An important piece of kit is your Buoyancy compensator device-BCD. You will want to choose wisely as BCD’s tend to last for a long time and can be expensive. There are many types to choose from although the main two available to recreational divers are jacket or wing. You could also consider back plates and harnesses although this choice usually entails that you may be diving doubles (Twin tank setup) and for the purpose of this discussion we will omit these choices.
Components of a BCD
A BCD is made up of three main components, the Jacket, the air cell and the inflation hose. The jacket is attached to the air cell and both are usually constructed of denier cordura a strong material that is resistant to abrasions and damage. The inflation hose connects to the air cell and a low-pressure hose is connected that draws air from the first stage regulator, which allows you to add air from the tank.
So what is the purpose of a BCD?
As I often explain to my students BCD’s have two primary purposes, to make you positively buoyant whilst on the surface and to make you neutrally buoyant whilst at depth. When you are on the surface you want you head clear above the water, so you will inflate your BCD fully. When you are diving at depth your exposure suit will compress and therefore you will become less buoyant and therefore, sink. To compensate for this, you will add small amounts of air into your BCD that will effective make you neutral.
Almost all divers will start off with a jacket BCD as your local dive shop will be probably be using these during training. Jacket BDC’s have one major disadvantage and when I am teaching new divers it always becomes and issue. When you fully inflate the BCD it places a lot of pressure on your torso and as a new diver this sensation combined with stress or cold water can make an uncomfortable situation. Another issue is that they do not allow for optimal trim in the water as the air is wrapped around you.
The alternative choice is a wing style BCD. These work by having the air cell only on your back that is attached to a harness. These types do not squeeze on your torso and allow for better in water trim. Some divers complain that when fully inflated on the surface they tend to push you face down in the water, although I have never experienced this problem myself.
My first purchase was a Zeagle Stiletto, I must admit I have been extremely impressed with this BCD. The only gripe I have is its integrated weight system, I would have much preferred a Velcro pocket solution. I like that it has two tank bands that help to keep it upright whilst walking and it’s light and perfect for travelling.