Wing or Jacket

Wing BCD Jacket

A wing style BCD has an inflation on the back, while a jacket "hugs" you. There are some distinct advantages and disadvantages to each.

Wing - Wings (left picture) leave your chest free and therefore it is easier to attach, detach equipment from it, especially staging cylinders. A key problem is that on the surface they will push the divers face into the water - an additional risk if you are unconscious. We see many divers going for the "tech" look, which is fine, but remember their are additional dangers involved for looking "techie" - you will need to make the judgement call to your own safety.

Jacket - Jackets (right picture) are the more traditional type of BCD. Often with large pockets for equipment, weight pockets, various D-rings for attaching kit. A good BCD can last your a long time - one of our instructors has been using his BCD since he started diving (2002) and the BCD still works well.

BCD Sizes

BCD Size Table

The table on the right is size chart from an slightly worn and older Oceanic user guide, it is a guideline only, every manufacturer is slightly different. Measure your chest with a thick sweater and then add 2" to your chest size (for dry suits). That should help to find the right size.

When ordering online, ensure you test the BCD before you go diving - if it doesn't fit return it. 

Ladies BCD - Women should consider buying a dedicated Ladies BCD, they are cut differently to their male counterparts. Some specific features include shorter jacket (i.e. slightly higher), which means weight pockets don't lie on the hips. Different shoulder strap location and enhanced front straps (e.g. Aqua Lung Pearl i3 BCD has an integrated chest support), making the more comfortable across the chest.

Lift and inflation

A vital sizing key for a BCD is the amount of lift the BCD is able to generate when inflated. Depending on the amount of "kit" you wear, the amount of lift required will differ. You can always use a larger BCD (with more lift) in warmer climates, but not necessarily the other way around. 

Here is a simple guideline for you:

  • Tropical Diving (shorty or only 3mm wet suit)
  • UK Recreational diving (5mm wet suit, dry suit)
  • Technical diving (dry suit, twin sets, demanding diving)
8 to 14 kg
10 to 22 kg

There are also many different inflation mechanisms. Manufacturers have been trying to differentiate themselves through some of these features - e.g. Mares Air Trim; Aqualung i3 and the Scubapro Balanced Power Inflator (BPI). Personally, the traditional Inflator hose, which has been around for a long time, works very well and when we teach, we use it - to ensure everyone uses the same simple equipment. 

Some BCDs offer an alternative air source at the end of the inflator hose, effectively diminishing the need for an octopus. However, this means you will need to get it serviced regularly (a normal BCD can easily be serviced by yourself if you follow the instructions - we recommend you get shown by an equipment specialist on how to service yours). The advantage is that it reduces your travelling weight, but they are quite bulky and do require a bit of practice to use them effectively.


Dump Valves

Dump valves allow you to purge the gas inside the BCD. A BCD should have at least two - one on the right shoulder and near the rear left hip. The inflator hose itself may also have a dump valve integrated (by pulling the hose - warning they can wear out quite easily). As a simple rule, so more dump valves to better it is - it is extremely important for you to know where the dump valves are located, so you can reach them by feel only.

D-Rings and pockets

D-Rings on your shoulder harness, the belt and on the bladder itself. So more D-Rings so better, allowing to attach key bits of kit without loosing it (e.g. compass, camera, DSMB). Large pockets are also helpful, allowing you store spare mask, a slate and other things you may wish to use underwater.

Travel BCD

Travel BCD are designed to be smaller and lighter and therefore minimise the weight you carry going on holiday. They have all the basic features as a large BCD, but often don't have metal D-Rings, but plastic ones.