A scuba buoyancy control device (also called buoyancy compensator, stab jacket, stabilizer, BC, or BCD) is a diving equipment that gives you control underwater.
It contains an inflatable bladder that ensures positive buoyancy on the surface and neutral buoyancy in the water when needed. By adjusting the air volume in the bladder, you control this device while diving.
Basic parts of a scuba buoyancy control device
Though these devices may have different components depending on their design, some basic parts are standard in all buoyancy compensators.
- Low-pressure inflator & oral inflation system: Inflator is mated to the power button and serves to inflate the scuba buoyancy control device.
- Deflator mechanism: This allows you to release the air from the aforementioned bladder and deflate your BC by pressing the certain button.
- Adjustable band, strap, or buckle: It is mainly placed at the back of the stab jackets. These bands hold the tank in place and allow you to easily change your tank when needed.
- Quick valves (dump valve and overpressure relief valve): Thanks to these valves, you can breathe out while diving without using the deflator.
- Pockets: They allow you to carry accessories, instruments, decompression tables, diving reel, and other things important for you. In most models, the pockets are positioned at both sides of the buoyancy compensator.
In addition to these main components, some BCDs also contain a diving weighting system (which eradicates the need to wear the weight belts), textile casing, metal or plastic backplate, crotch strap, cummerbund, D-rings, hose retainers, emergency inflation cylinder, bungees, padding for comfort, and reflective band for better visibility.
Each BCD style has its advantages and disadvantages. Though some scuba buoyancy control devices are more suitable for a particular diving type, most of them can be used by beginners and the most experienced divers. These are the most common BCD styles:
- Jacket style: This is the most popular and the most common BCD style, especially when it comes to the recreational scuba diving. Jacket BCs are fitted over the chest and around the neck. These buoyancy compensators are mostly secured by straps between the legs and around the waist alike. Some stab jackets are specially designed for women.
- Back inflation style: The back inflation BCDs only contain a rear air bladder, which provides more space for the chest area. Those can easily lead you in a horizontal position underwater.
- Wraparound BCDs: The wraparound bladders are popular among divers who want to maintain an upright position on the water surface.
- Hybrid BCDs: The hybrid air bladder style allows you to get a horizontal diving position and low front clutter. Aside from that, those BCs provide a more comfortable and relaxed vertical orientation either when you dive on the surface or kneel on the bottom.
- Sidemount BCDs: Sidemount systems combine a harness system with a back wing. In those buoyancy compensators, the tanks go on the sides under a diver’s arms. This way, you can avoid heavy double tanks on your back while diving. Sidemount style is particularly suitable for diving in tight areas like cave diving.
How to choose your scuba buoyancy control device
When choosing your BCD, take into account these tips:
- Pay attention to the size of a buoyancy compensator. Try out a few sizes and select one that fits you well. In order to get the snug fit, take into consideration whether you will wear a thick wetsuit or drysuit.
- Choose a BCD based on your gender. Women’s buoyancy compensator have shorter torso while men’s BCDs come with longer ones. That’s because men have longer backs than women.
- Also, you should consider which type of diving you are going to do. The jacket style BCDs are good for the recreational divers, especially for diving on the surface. Wraparound buoyancy compensators tend to push the divers forward into the upright position and are suitable for deep diving. Those with a side-mount system are perfect for cave diving.
- Bring your regulator with you to check out if it is compatible with the inflator hose.
Once you narrow down your choice, consider color, design, optional features as well as your personal preference, and choose a scuba buoyancy control device that suits you best.
Please, left a comment with your own experience or questions about purchasing/finding a BCDs.
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Very cool. Thanks for providing us with all the details we need when purchasing a BCD. I have never been diving but knowing these details would help forsure. I love how you offer insight on different styles and give us tips on how to choose the right one. Maybe I’ll go diving sometime soon now. Thanks for sharing!
Thanks for your comment Rob.
I only can say that you should try it. If you need to find a reason, just read the post I wrote about it 7 Reasons to become a scuba diver
Thank you for this overview of what a BCD is, I dive when I can and did know there were so many types and configurations.
I am thinking about buying my own BCD but the amount of options in the market is overwhelming. There are so many brands with different bells and whistles that I don’t even know where to start in my filtering and selection.
Could you make some recommendations as far as to which brand/model you would recommend for an amateur recreational diver?
Thanks for your comment.
At the moment I’m working in some reviews of BCDs. Soon will be published on this website.
However, as a quick reply to your question, I can say that the Mare Prime MRS is a good option.