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Choosing the right back inflating system for your BCD

All you need to know about horse shoe and donut shaped bladders


When it comes to back wing BCDs, there are two primary designs to consider: donut and horse shoe shaped bladders. (read about the comparison between back inflating BCDs and Jacket style ones on the article Choosing your first BCD. All you need to know about different BCDs styles). While both types of wings offer pros and cons, understanding the differences between the two can help you choose the right one for your diving needs. We are about to explore the differences between donut back wings and horse shoe back wings.

Horse shoe bladders

Horse shoe bladders get their name from their U-shaped design. This type of wings provide excellent stability in the water. The design distributes the gas evenly around the diver's body leaving a gap at waist height between both sides, promoting balance and control.


A great advantage of horse shoe wings over other bladders is that they allow trapping air in one side of the bladder while in trim position. This feature provides the ability of a customized distribution of its lifting capacity in order to compensate the unbalance, when carrying extra tanks on just one side of the body for example. However, this factor may also present horse shoe bladders main disadvantage, since the correct use of it may require a great buoyancy control and expertise and might not be suitable as a first ever wing.


In addition, a possible drawback of the horse shoe shape is its air dumping valves. Some of these designs only possess valves on one side of their bladder, which means that the gas inside the bladder will have to make its way toward the exit point before being vented out. Nevertheless, some modern designs have overcome this by simply adding an additional valve, having now one on each side of the ends of the wing.

horse shoe bladder bcd

Donut shaped bladders

Donut bladders get their name from their round, donut-like shape. This type of wing also provides excellent stability underwater, being somehow easier to control by divers with less experience using back inflating BCDs.


Donut shaped designs allow for a free circulation of the gas inside the bladder and a somehow self-adaptation to the divers body position. This feature promotes an easier achievement of a streamlined body orientation.


Due to its round shape, donut wings also provide a great and even bottom lifting capacity. In cases where divers should wear weight belts or heavy pouches, these bladders can present a solution to the hip positioned center of gravity.


One last feature of donut shaped bladders is that they do not necessarily need to be round. There are several donut shaped wings that have adapted their shapes to provide a more customized lifting capacity such as horse shoe bladders can.

three types of donut back wings

Choosing the right wing

While prices of theses wings can be different, this fact is not only related with their design. As back wings are used both for recreational and tec diving, they differ on designs, sizes, lifting capacities, shapes, materials and accessories such as a gusset control systems to prevent the loss of shape of the bladder. The considerations to have are related with the type of diving and, the kind of diver you are when choosing one.


When purchasing your wing, you should account for the lifting capacity you will need, to pull all your equipment and yourself. This will include knowing the size of your tank and, if you will use it for single tank setting, double tank or CCR. The shape of the wing might determine your level of comfort, so thinking about the need of some more bottom or top lifting capacity will help you figure this out.


You have to try to avoid the “hot-dog” or “taco” effect. If thinking about the tank as a sausage, if the bladder is to big, as air is pumped in it, the bladder will bend upwards somehow wrapping the tank around. This effect will reduce your control over the air inside you bladder, consequentially reducing your control over your position underwater.


If your goal is to penetrate narrow passages exposing your wing to sharp objects like wrecks, consider a rugged material to prevent punctures underwater. A gusset control system may also help to keep the shape of the wing in place, but can risk entanglement.


Approach your trustworthy retailer for more information and do not hesitate to shoot us a message if you have any further questions about wings or BCDs. HAVE A NICE DIVE!

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