BCD mistakes that many divers make – not just the “newbies”

Mistakes are mere echoes from the past. Let’s not repeat it but just learn from it.

Every diver makes mistakes during their diving, the secret is to learn from them and improve. Here is how to avoid the most common mistakes when you are using your BCD.

Old Timers can remember when we did not have BCD’s.
The modern BCD is a very impressive piece of gear, however many divers use the BCD as their primary buoyancy device. Your lungs are your primary buoyancy device, your BCD is there to keep the tank on your back, enable you to float safely on the surface and ASSIST with GETTING NEUTRAL UNDERWATER.
(OK a modern BCD will do much more but please, Keep that thought in mind as you read on).

1. Not knowing how a BCD works. 

During your Open Water Course, you learned how to operate a BCD, but was it the BCD you are wearing today?

Of course, if you have your own gear, after a few dives, you and your BCD will be as one and everything will just fall into place as needed.

But what about that rental BCD? Have you taken the time to find out how it really works? Where is the inflator button? How hard do you need to push it? Same for the inflator button.

Can you disconnect the inflator hose in an emergency? Can your orally inflate if if necessary?

Do you know where the dump valves are? Shoulder dump? Rear dump.?

If the BCD has integrated weights, do you know how to check that these are secure and how to ditch in an emergency?

Did you take the time to work all this out during your gear check? You did of course complete a gear check on that rental gear or are you doing your entire dive on a “trust me” basis?

Of course you know all this about your buddies BCD as well,? or did you also skip the buddy check?

I replaced my BCD recently, my old one had served me well for around 1K dives. The rear dump on my new BCD in on the left, my old one was on the right. Even after 20 or so dives in the new BCD I was still reaching with my right hand for the rear dump, “muscle memory” once developed stays with you for a long time.
This is my current BCD, Scubapro Hydros Pro.

2. Not using the BCD properly at the surface.

“How can I not use my BCD properly at the surface” you may ask, “I simply fill it full of air so I can float, right?”

Well, there is a little bit more to it than that, on the surface you only need to put enough air in your jacket to float, enough air, no more. Why? because overfilling it will make it harder to move on the surface and will restrict your chest and consequently make it harder to breath.

Overfilling a “wing style” BCD will probably push you over onto your face.

Like most things in life, “just enough” is plenty.

3. Overusing the BCD underwater.

Do you look a little like a Puffer Fish underwater?

Air in, Air out, Air in, Air out, Air in, Air out, and on it goes throughout the entire dive.


Your lungs are how you should control your buoyancy, if you don’t know how, then you need more training.

If you are properly weighted you should only need a little air in your jacket at the beginning of the dive (compensating for the buoyancy difference between a full/empty cylinder) and probably a little more as you increase your depth.

The first step here is to be properly weighted, when was the last time you did a weight check? Has anything changed since your last weight check? wetsuit? body fat? cylinder type?

Compensating for extra weight by putting more air in your BCD will spoil your body trim and you will use much more air.

In addition to the weight check you were taught on your Open Water Course, there is a very good method for finding out if you are properly weighted:

At the end of you dive, with 500 psi in your tank, at safety stop depth, you should not need any air in you BCD to keep you from sinking when you let your body go limp.

If you still need air in your jacket at this stage then you are over-weighted  and have been for the entire dive.

The benefits of proper weighting are that you will use less energy to move through the water and subsequently use less air, more dive time for your money, that has to be a good thing.

My students will testify that during my courses I am really, really keen on correct weighting, proper lung control and excellent buoyancy control.

If you are struggling to get this right, consider a Peak Performance Buoyancy course. With a good Instructor you will be amazed how much your buoyancy can improve in just 2 dives.

Share with your friends

Leave a Reply

Your email address will not be published. Required fields are marked *