• Marine Conservation

Understanding your dive equipment: BCD’s

Posted: August 26, 2020

Choosing the best BCD for you


Ever wanted to know how to select the right dive equipment for you? In this blog we look at the BCD and show you some hints and tips into fitting and selecting a BCD.  When joining a diving program it can be daunting prospect looking at all the diving equipment and not being too sure where to look or what to buy. Here, we hope to shed some light on the BCD and what to look for when buying, renting, or borrowing one.


What is a BCD?


BCD stands for buoyancy compensation device but also can be know as a BCJ buoyancy compensation jacket. It is designed to keep you afloat while on the surface of the water therefore making you safe but it is also designed to help you become neutrally buoyant underwater when needed.


What is neutral buoyancy?


There are 3 types of buoyancy: Positive, neutral, and negative. Negative is when the object is denser than the fluid it displaces. Positive is when the object is lighter than the fluid it displaces and neutral is when the object is equal to the fluid it displaces. You may find that when you first go diving that you have your BCD fully inflated on the surface and you float. You are positively buoyant. When you decide to go under the water and descend, you release the air slowly to control your descent. As this happens, you become more dense than the water and therefore you descend. As you don’t want an uncontrolled descent and go crashing into the floor potentially harming the underwater wildlife or yourself, you use a BCD to add a bit more air to then make yourself neutrally buoyant.


How do I fit a BCD?


As you take your first step into the diving world ask your instructor or divemaster to show you how to properly fit a BCD. If you are still not sure, any reputable dive center will be able to assist you as well. A few hints and tips though:

  • It should be comfortable but snug.
  • Fully inflate it. It should not be too tight on your body or restrict breathing.
  • Move around in it. It should allow you a full range of movement and avoid pinching.
  • Make sure all aspects of the BCD are within reach of you and not just others.

What BCD styles are out there?


The most common is a jacket style BCD ( can be called a vest). When inflated, the bladder (the section that holds the air) is around the front, back, and sides of the BCD. They are normally an excellent entry style BCD with pockets on the side. It would be easy to try one on as most rental BCDs are of the jacket style. The next style is the back inflate BCD where the bladder is only on the back of the BCD. Some come with wrap around pockets and some do not. These can be more comfortable and have less squeeze over the whole body like the jacket but when fully inflated on the surface, these back inflate BCDs can tend to make the diver fall forward if they are not used to it.

The Cressi Start BCD used here in the Seychelles. This is a Jacket BCD that has front, back, and side inflation. It allows for full movement and good comfort for it’s range with easy access pockets. Everything you look for in a introduction BCD.


What weight systems are included?


If you find the weight belt weight system too uncomfortable you can look at opting for an integrated weight system with the BCD. Again this is personal preference and what you find most comfortable. Some people use the weight belt, some have a padded weight belt (both options separate from the BCD) and some have the integrated set up where they are attached to the BCD on the sides using a quick release system like a buckle.

Is there anything else I need to consider?


There are specific fits for females now. Before diving used to be dominated by males but that has changed now. Because of this, there are BCDs designed to fit the female body more comfortably so this is something worth considering. Are you also planning on going travelling and diving at the same time? If you like to have your own equipment now then weight will come into it and there are complete travel ranges of all equipment.

What BCD is best for me?


Just like anything in diving. It is all about comfort! On your first few dives, use the dive shop or dive center BCDs. Borrow one from a friend or family member to try out others. See what straps can potentially cause discomfort and which ones do not. Then head to your nearest store to try more on and find out what is the best fit for you. It is not a one size fits all scenario. The staff here at Cap Ternay all swear that their BCD is the most comfortable and when wearing someone else’s how uncomfortable it is to use.


What the team has to say!

“I love my back inflate BCD. I have the Scubapro Hydros (the same as my wife) and it is the perfect fit for the both of us. We didn’t plan it, it just turned out that way. The reason we chose these BCDs is first of all comfort. Secondly, we wanted a pack-able lightweight BCD for when we go travelling. In a warm water climate we can pack our BCD and regulator setup in the backpack it comes with, attach our fins to the front, and it still all comes under 10KG. To us that is perfect! “

Luke Searle-Evans, Program Manager and Dive Instructor, Cap Ternay, Seychelles


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