Buoyancy Compensating Device

Buoyancy Compensating Device

JoJo Southgate ·

A Buoyancy Compensating Device (BCD) is one of the most expensive pieces of dive equipment you will buy, so it’s best to look after it so you can get the most out of it.  These come in all different varieties and choosing the right one can be quite a hard decision. It will need to tick all the boxes for ‘your kind of diving.’ 
For example, if you only plan on diving whilst on holiday and staying at recreational depths then a simple travel BCD may serve you well for many years, however, if you plan on diving several times a month in the Summer, as well as on holiday then a more robust standard BCD would suit you better.  For those that plan on diving several times a week all year round at deeper depths as well as recreational depths then a higher-end BCD or a wing may be a better choice.  Pop into your local dive centre for a chat with them and to discuss your needs.  Don’t just buy the first one you see because it was on offer at a good price – there’s probably a reason it’s a “bargain”!

So, what is a BCD?

A BCD, short for Buoyancy Compensating Device, is a piece of scuba diving equipment that you wear to control your buoyancy in the water. There are 2 types of BCDs that you can purchase - jacket-style BCD or Wing. PLEASE DO NOT ATTEMPT TO USE ONE WITHOUT THE PROPER INSTRUCTION.

Jacket-Style BCD vs Wing.
There is no better or worse of the 2 - although some divers may argue that - at the end of the day, it's all down to your own preference and your needs. Here's a bit of information on the two:

Jacket-Style BCDs.
The main feature of this is that the BCD will inflate around your upper body.  The air bladder design in these BCDs means that the air will inflate in the waist and chest areas with little on the back.  This means that when underwater its makes it a little more difficult to achieve that streamline, horizontal position.
These tend to have nice, big pockets which can be handy for either weights or storage of small items that you won't need to access quickly.
Other standard features include:
- Inflator Hose
- Dump Valves. These can vary for each manufacturer/model - one BCD could have 2 (shoulder and back), the other could have 3 (shoulder, back and pull on the inflator hose).
- Releases. Again, these vary. Some have clips others have buckles and they can be in different positions.
- Shoulder straps. Generally in the same place(!). However, there can be 1 difference. Some manufacturers offer a 'ladies' version of a BCD, these fit more comfortable as they accommodation for our ladies bumps. The straps will fit around and at the side of the chest area as opposed to sitting on top (and potentially squashing anything).
- Weight pouches. Tend to be in the newer jacket-style BCDs.  Located mainly at the front, you can also get trim pockets on the back of the BCD that goes either side of the cylinder.  These tend to be quick-releases so they can be pulled out if the need arises, but they will hold a maximum weight so make sure you check with the manufacturer guide so you don't overload them.

The main feature of this is that the wing will inflate behind you, between you and your cylinder.  The diver wears a harness that attaches to a donut or horseshoe shape BCD, which then attaches to the cylinder.  They are available in a single and double size for diving on single and/or twin cylinder sets.  As the wing sits on your back, this is where the air sits which gives you that better, streamlined horizontal position in the water. They don't tend to have pockets. Features of a wing differ slightly than the above:
- Inflator Hose is the same.
- Dump valves also tend to be the same. Although they are mainly located only at the bottom of the wing.
- Releases. These can be different, as the harness is a different make-up of the jacket-style. Each manufacturer differs, you'll find that some have releases on the arm straps and others don't and that some have a buckle release rather than a clip.
- Shoulder straps. Not as nicely padded as some jacket-style BCDs as the straps on the harness tend to be webbing - no ladies fit either.
- Weight pouches.  Available for wings too. 

You can purchase Wing BCDs - these are a mix between jacket-style and wing BCDs. The main features here is that there are thicker shoulder straps for comfort and pockets for storage.
You can also purchase travel BCDs that are mainly lightweight. They tend to be less robust as they have a thinner material (to save on weight and bulk) with fewer features.

Buying a new BCD.

Like anything, always do your research before making such a big purchase. Have a chat with your instructor about your diving and what you intend to do with it - they can recommend what style will suit you best. Talk to your local dive centre and instructor about what you have in mind and see if they have something that you can borrow to try it out before buying - especially if you've learnt in a jacket-style but prefer the sound of a wing. Browse online, have a look at what different manufacturers have to offer and chat with other divers for advice.
But ultimately, just remember the decision is down to you - there's no right or wrong decision. If you're buying a second-hand BCD make sure that it is in a good condition and in good working order before you buy it. It is advisable to purchase one that has had a recent service and once you've received it maybe try it out in a pool or at a shallow depth before embarking on a dive.
Don't forget to support your local dive centre! Chances are they will give you a good deal if you go to them for advise and keep going back.  Like any other small business, they appreciate the support.

General Care

  • After a dive always give your gear a good, thorough rinse. Especially if you’ve been diving in saltwater, the salt will crystallise on and inside your gear which will cause you problems later on.
  • Always empty the water out of your BCD after a dive. This ensures that water (especially salty water) doesn’t stay in the bladder which can cause crystallisation and mould.
  • Avoid long exposure in direct sunlight. Not only can this fade the fabric but any extreme heat may damage the welded seams of the BCD’s structure.
  • Make sure it doesn’t come into contact with any sharp objects or rough surfaces – these can abrade or puncture the material, leaving you with a leaky BCD that will need repair work. With this in mind, make sure your dive knife (and anything else sharp) is safely tucked away in your dive bag before placing your BCD inside it.
  • Avoid repeated/long periods in chlorinated water. These chemicals can cause the fabric to discolour and decay quickly.  You’ll notice that most of our team use different BCD’s in your confined session and open water session – this may just be an older BCD in the pool so their new, shiny BCD/wing can stay nicer looking for longer!
  • When drying out your BCD fully inflate it. This will ensure that all parts of the BCD dry out effectively and don't stick together. It’s also handy because if you notice it has deflated (even slightly) when you come back to it then you know you have a leak to look for – more on this later.

Pre & Post Dive Checks and Servicing

When you’re checking over your kit and preparing for a dive it’s always best to double-check that your BCD is in working order rather than just making sure it’s in your bag. Orally inflate it and set it to one side while you check the rest of your kit. Before putting it to one side, glide your hand over to see if you can feel any air releasing. Once you’ve given it some time make sure it’s not deflated – if not, great!  If it has, you may need to do some emergency patchwork to hold it for the dive, so take it to your local dive centre to have a look.  Another great way to look for leaks is by inflating it and submerging it into some water (bath, dunk tank, paddling pool etc), look for any bubbles escaping and if you need to do some repair work make sure the BCD is fully dried before doing so.
Make sure that all functioning parts are fully operational. Does the inflate and deflate work? Do the dump valves work? Is the tank band threaded correctly? Are your releases ok?

After your dive make sure you extract any water inside straight away before packing it back into your bag.  Fold it up neatly into your bag (away from those sharp objects!) and store your bag/box appropriately before getting home.  Once home, unpack your dive gear and rinse it off.  As mentioned before this is especially important if you have dived in saltwater.  Orally inflate your BCD to dry it or use a BCD hanger, remember don’t leave it sitting in direct sunlight for a prolonged amount of time.  Work any zippers up and down a few times to ensure they are free from any sand/gritty particles and every so often give them a bit of a wax along the top.  Clean off any Velcro parts, small particles such as sand – I’ve even seen stringy algae attached! – can get stuck in between the Velcro bits so give them a good brush off.  Then store appropriately.

Having your BCD serviced annually is highly recommended.  This will consist of: all wearable parts inside the inflation system being replaced, a thorough clean of the inflation system, and sterilization of the inner bladder.  Do not attempt to service your BCD on your own – please note, some manufacturers will void a warranty on a product if you don’t follow their recommended guidelines (i.e. annual service) or if you tamper with the product yourself.
It is also worth noting at this point that if you book onto a course and use your own scuba diving gear the dive centre and/or instructors may ask for proof of service to ensure that the BCD has been checked recently and is in working order.

Using weights in your BCD.

Some BCDs contain weight pouches and pockets.  These are really handy, especially if you’re like me and don’t like wearing a weight belt!  It is highly recommended that you use shot weight in your BCD as this is much softer than a block weight, they also mould to its surroundings 😉 making it more comfortable for the diver.  With a block weight, not only is it hard and uncomfortable if it’s pressed up against your hip bone but over time the corners of the block can wear away at the fabric of the pouches which cause fraying and small holes – although these small holes don’t affect your use of the BCD it’s not always a great look and can be disappointing if you’ve not had the item that long. 
If you have pouches that clip in via a click method or a pinch clip method MAKE SURE THEY ARE CLICKED IN SECURELY AND YOU HEAR A CLICK! I can’t tell you how many times we’ve seen pouches lying on the bottom or being lost because it’s not been secured properly – and they’re not always retrievable, so not only do you lose a pouch you lose your weights too! Make it part of your buddy check to ensure that all weights are securely in place – let's face it, the last thing you want is to have to end a dive because you’ve become too buoyant because they’ve fallen out OR it’s fell out and hit someone (you won’t be too popular if that happens!).
Another thing to add here is to make sure that each side is equally weighted – you don’t want to be a wonky diver, at best you’ll earn someone else £250! 

How to store your BCD

Once you’ve cleaned down your BCD and it’s dry there are several ways you can store it, and it’s up to you how you do this – there is not necessarily any right or wrong in the below (unless it’s soaking wet and deflated):

  • It’s recommended to always store your BCD partially inflated in a cool, dry, clean place away from direct sunlight. There are several reasons for this:
    - Storing it partially inflated will prevent the inside from sticking together.
    - Out of direct sunlight as explained above.
  • Back in your bag/box. Fold it up neatly and place it inside your dive bag or box, away from those sharp objects.  Although this isn’t the best way to store a BCD we understand that not everyone is blessed with space, however, if you can get a tiny bit of air inside the BCD before folding it so that the inside doesn’t stick together.  If you can get away with putting the BCD on top of your bag (so it’s still out the way) then that would be a better option in this scenario.
  • On a Hanger. There are BCD hangers that you can buy, they have an ‘edge’ on them, this stops your BCD sliding off the hanger.  Simply hang it in a suitable place, partially inflated.
  • Safely out the way. If you don’t want to store it in your bag or box and haven’t got a suitable hanging place just partially inflate it and place it down somewhere dry, clean and out of the way.

Remember to remove any weight out the pockets/pouches and anything that’s clipped onto any areas of the BCD.  This will stop any unnecessary strain on the BCD.
If you are storing your BCD for a prolonged amount of time (longer than 2 months) it’s advisable to put a small amount of silicone grease onto any rubber parts, but not the oral inflate mouthpieces.

If you want some advice on BCDs or need anything to help you maintain your BCD get in touch or pop into the centre.  We stock a variety of suitable items such as BCD hangers, Aquasure for repairs and can also provide servicing.

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