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Home › Diving Info › Equipment › Buoyancy Control Device

Scuba Buoyancy Control Device

A buoyancy compensator is an inflatable jacket or vest used by scuba divers to control their buoyancy underwater and at the surface.

In fact, the scuba buoyancy control device (BCD) is one of the key pieces of equipment needed for assembling the dive gear.

What is a BCD Vest and How Does it Work?

In general, the various BCD parts and components used for buoyancy compensator jackets are standard.

For example, most types of buoyancy control device (BCD) will have:

• An air bladder (usually made of Cordura® - a durable and puncture-resistant material)
• A low-pressure inflator hose assembly for inflation and deflation.
• A sturdy backplate and harness mechanism with buckles for attaching the scuba cylinder.

Hence, a scuba BCD has several important features. The vest integrates with a harness so you can strap the tank on your back. It has pockets for storing diving accessories and straps for securing gauges and the octopus.

It is fair to call it an inflatable vest and backpack all in one because it is a wearable item to which all of the other gear is secured.

A buoyancy control device (shortened to BCD) is the main part of a scuba unit that allows the diver to gain control of, and fine tune, buoyancy in water.

Using either a manual or oral inflation mechanism, a diver can pump air into the internal bladder of the buoyancy jacket (e.g. to float effortlessly at the surface). Then, pressing the deflator mechanism releases air when the diver is ready to descend.

BCD Scuba Gear Setup

A BCD vest secures a scuba tank via an integrated harness. In fact, some buoyancy compensators allow the fixing of two tanks (double cylinders) attached to the back plate, such as when deep diving or Technical diving.

BCDs usually have several pockets, snap clips, and Velcro® straps to stop regulator hoses and instrument gauges from dangling.

Most divers call the second stage alternate air supply an 'octopus' because the long hoses resemble the tentacles of the common octopus species.

Key takeaways:

As a rule of thumb, a scuba diving jacket sits over the upper body of the diver (the torso), and is firmly fastened together using a combination of belts, buckles, and straps.

In other words, when choosing BCD diving equipment, you should be considering several important features from a scuba buoyancy vest, including:

• Does it feel comfortable with a 'snug' fit?
• Is the lifting capacity sufficient for your type of diving?
• How sturdy and reliable is the construction?
• Does it have an assortment of quick release straps and connectors?
• Can you reach the pressure release valves with ease?
• Does it have an integrated weight system (removing the need for wearing a weight belt)?

BCD with Integrated Weight System

Some modern BCD vests have large sturdy pockets for carrying solid lead weights inside. You can also use some smaller trim weights in various other positions of the BCD jacket.

Some of the advantages of this system are that it removes the need to wear a weight belt around the waist. This can be cumbersome and uncomfortable for "larger than average" size divers.

Plus, many divers appreciate the ease at which these weight pouches can be easily removed. For many, this is an important feature in scuba diving emergencies.

Which BCD is Best For You?

There are many buoyancy control device reviews offering impartial advice about the different models and styles. We recommend going to a good specialist and actually trying on various jackets until you find a good fit.

Some will appeal because of the design element. But, you'll need to get your body inside it to see which you feel most comfortable with.

Keep in mind that it will feel different in the water. Generally, if it feels good out of the water, and you feel good about it, you can be sure of having made the right choice.

But wait - there's more:

The tank band strap of the BCD will be unused and it should be made wet immediately before it is used to secure the scuba tank during equipment assembly.

The main reason is that when it comes into contact with water the strap expands, which may lead to the cylinder becoming loose underwater.

Whatever style of scuba BCD you choose, some things to consider are proper fit, lift capacity, good construction, reachable pressure release valves, comfortable, quick-release straps, and pockets with zippers.

Pro Tip: It takes time to get used to a new BCD. PADI scuba training courses focus on this, including the Scuba Equipment Specialist and the Peak Performance Buoyancy Specialty courses.

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