USU SCUBA Club

Buoyancy Compensator

A Buoyancy Compensating Device (or "BCD", or just "BC") has two main functions: It allows you to adjust your buoyancy underwater, and it holds the tank on your back while you're diving. Additionally, it also helps you manage your gear: most BCD's have clips, buckles, and attachment points for the various other things you have with you: your regulators (especially your backup second stage), your gauges, your weights (with weight-integrated BC's), etc.

There are several styles of buoyancy compensators. Perhaps the most common is the "jacket-style" BC, in which the air bladder wraps around you a little at the sides. Some people find that this design can be restrictive while diving (especially with older BC's), and prefer a "back-inflation" type, where the entire air bladder is located on your back, where it won't squeeze you when fully inflated. One criticism of back-inflation BC's is that if you inflate it too much while you're upright on the surface, it may tend to push you towards the water face-first (so just add as much air as you need to stay positively buoyant rather than filling the entire thing).

One of the big choices with BC's is whether to get a weight-integrated one. Most divers need to wear extra weight while diving to offset their own natural positive buoyancy and that of their wetsuit or drysuit. This is usually worn in one of two places: on a weight belt, or in special quick-release pouches that are inserted into the BC. In both cases, the weight is easily releasable, which is important in extreme situations where you may need to reach the surface quickly. There are advantages and disadvantages to both. With a weight-integrated BC, you omit one piece of gear (the belt), so you have a little less to carry around. When you're putting on the BC though, you have to lift the extra weight of the lead in addition to that of the tank, making the unit quite heavy. While it's possible to put the unit on and then insert the pouches, this is often quite difficult once you're wearing it. With a weight belt, the weight is already worn around your waist before you put the BC on, so it's easier to get on. Additionally, certain procedures underwater (like entanglement) may require you to take your scuba unit off and deal with the situation. If your weights are in your BC and you aren't wearing it, you're going to be floating upwards and may have a more difficult time with something like this. If you're wearing a weight belt, the weight is still on you and you won't have this problem. Some people may wear weight both on a belt and in integrated pockets, either by choice, or because the BC pockets don't hold enough for them. Many styles won't hold more than about 20 pounds (this, and the amount of weight you'll need to carry, are good things to know before you buy a BC).

If you think you might ever want to do any technical diving (requiring additional training, since it will lead you into situations outide the realm of simple recreational diving), you may consider a "backplate and wing" system. Many divers like the simplicity and flexibility of this configuration, which allows easy customization for diving in different conditions.

Most new BCD's cost between $200 and $500. Try on as many as possible before buying one, since it's one of the more expensive pieces of equipment, and you want to end up with one that feels comfortable and does what you want it to.

Next page: Choosing a Regulator Set