HOW TO USE YOUR BUOYANCY CONTROL DEVICE?
The buoyancy control device, or BCD in “diver speak”, is one of the essential components of your diving equipment. Not only does it hold your tank, this equipment will also help you to adjust your buoyancy, to stabilise yourself in the water, and to control your progress when surfacing or descending. But first you have to know how to use it…
Julien, diving equipment product engineer at Subea, provide some advice for correctly using the purge (or dump) valves on your buoyancy control device, to help you keep your balance!
USING THE PURGE (OR DUMP) VALVES ON YOUR BCD

WHAT DOES A BUOYANCY CONTROL DEVICE LOOK LIKE?
Your buoyancy control device includes an inflator, which is used to inflate / deflate your BCD through its connection to your regulator.
It also has a so-called “slow”, more precise purge valve (also known as a dump valve), as well as 3 “quick” purge valves, including:
- one on your shoulder, to be used in a vertical position (head up): the ‘upper purge’
- the other at the base of your back, also used in a vertical position, but this time with your head down: the ‘lower purge’
- a third valve (known as a ‘Fenstop’), operated by pulling on the inflator in case of emergency.
Any of these purge valves will enable you to deflate your BCD and therefore lose buoyancy. However, it’s better to use certain ones in case of emergency. It’s also very important to be able to locate your purge valves quickly and easily while underwater.

MAINTAINING YOUR BUOYANCY CONTROL DEVICE
Knowing how to use your BCD is important for your safety, but so is making sure it’s properly maintained! Now that you know everything about your BCD, be sure to inspect it thoroughly after every dive, as upkeep is essential for equipment to remain in full working other. Check out our other tips for properly taking care of your equipment!
Advice link: maintaining your buoyancy control device
ARTICLE CO-WRITTEN WITH

I’m a diving equipment product engineer at Subea. I began diving as a teenager, but it was only after I started my job that I really developed a passion for it. I decided to get certified and go through the various levels of training, and now I’m a PADI Rescue diver with “Deep” certification.