Choosing a BCD can be a daunting task, there are so many different ones to choose from. Jacket or wing, backplate or not, what is lift and how much do I need? The type of BCD used can have a big impact on you're diving experience. Are you a recreational diver or technical? Perhaps you're a bit of both? Let's talk about the different types of the BCDs so you can choose whats right for you.
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Jacket BCDJacket BCDS are one of the most popular types, you will use or most likely used one in your open water training. It is called a jacket because it wraps around your body. Some of the advantages of jackets style BCDs is that they have pockets, built in weight systems and it gives you more stability when you're on the surface. Some of the disadvantages are they tend to be bulky and the inflation can sometimes cause squeeze around your waist. But over all they are the workhorse of scuba meeting most divers needs. |
WING BCDWing BCDs can look very similar to jacket BCDs, sharing many of the same characteristics. Some call them hybrids. This is a popular style for more advanced divers and those making their way towards tech. They can have built in weight systems and pockets just like a jacket style BCD but the main difference is the part that inflates is only on your back. The advantages to this type are they are more streamlined giving you greater range of motion and eliminate waist squeeze. The disadvantages are they can be front heavy if you are using a lot of weight which can make it tricky to stay upright on the surface. |
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BackPlate and wing BCDBackplate and wing BCDs are streamlined to the next level. They are popular with technical divers and those who want complete control over customizing their BCD. The advantages are different wings sizes and shapes can be used and they can be changed by the diver. They use a diver configurable backplate that is made of steel or aluminum. They can be plastic as well. The straps tend to be bare bones and can be configured to the users liking, many opt to add a crotch strap for added stability. Weight systems are of the divers choosing and can be placed wherever they feel comfortable. The inflater system can be modified as well. The configurations are only limited by your imagination giving you the ability to dive with 1 tank or 2. If you are adventurous even more. The disadvantages of a backplate system are they require a lot of dive experience, adjusting a rig for a perfect fit can be very time consuming. It is not advised to use this type of BCD until you are very comfortable and confident in the water. You should also have an understanding of how mechanically a BCD works. |
LIFT
Lift is a BCDs buoyancy capacity and can range from as little as 19 pounds to as much as 45 pounds or more. A common misconception with lift is thinking it's how many pounds a BCD can lift when it's actually how many pounds of water a BCD can displace.
A diver with all their gear may weigh 200 pounds, but because of the density of that gear they may only displace 180 pounds of water. This means they will sink because there is a 20 pound difference in displacement. A BCD that can displace at least 21 pounds of water will make them float. In reverse a 200 pound diver that displaces 205 pounds will float. We add weights to compensate for that. Here's the mind bender, 6 pounds of lead won't be enough to sink unless it can displace 6 pounds of water "Huh, what's this guy talking about?".
Lift is based on Archimedes' principle.
The upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces
Lift is important when choosing a BCD or a wing. If you are a warm water casual diver, 19 pounds of lift may be fine. But if you are a technical diver using twin steel tanks, a drysuit and accessories, 45 pounds of lift may be more appropriate.
BCD Functionality and FITBCDs have many features designed to streamline them and make operation for the diver easier. Some have weight systems with pockets that are pull to release, others have unclip and pull. Some have weight pouches that you unclip and the lead falls out. Others don't have a weight system at all. The biggest features to look for are in the inflation system. Is it a standard over the shoulder inflater? Does it have a pull to deflate feature? Or maybe it's a side lever inflation system like the image to the right. Some even take it a step further and add what called an Air 2 to the inflater system. This combines a secondary regulator to the actual BCD meaning one less hose. Some may appreciate that it streamlines their configuration but it comes with its drawbacks. It takes extra training to use correctly, the inflater hose is non standard and servicing is very expensive. But despite that, there are many options to choose from. BCD fit is probably the most important thing to look at, not everyones body is the same. Several brands make BCDs specifically for women and it makes a very big difference. BCDs like the Scuba Pro Hydros fit their wearer like a glove while others have extra padding and even include lumbar support. |
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The biggest piece of advice I can give to anyone about buying a BCD is wait until you figure out what kind of diver you want to be. If seasonal warm water diving is your passion, a travel BCD may be for you. If you straddle the world of warm and cold water diving maybe a wing style BCD will meet your needs. Like diving with more than one tank or looking to go tech? A backplate and wing would probably be your best bet. Then of course there is sidemount which is a completely different animal. While I love it, it should not be your first purchase unless you are absolutely sure.
Try out different BCDs if you can and get a feel for what you like because they are not a cheap investment. I know the urge may be hard to resist when you go to your local dive shop and run your fingers over that ribbed inflater But take it from me, a person that has enough BCDs to equip a seal team, you should wait to see what kind of diving you like which will determine what BCD is best for you..