Buoyancy Control Devices (BCs) FAQ

Products - BCs


In our opinion a typical size metal backplate is suitable for divers with an average build between {5 ft 3 in | 1.6 m} and {6 ft 3 in | 1.9 m} tall. For more information about solutions if you are outside that range, see our tektip Backplates and Your Height

With the exception of the Apeks WTX harness system, none of the soft plate and harness systems we sell have provisions for adding a rigid metal plate. This is an often requested feature, but for many if not most divers this "hybrid" approach does not provide a benefit. For more information please read our tek-tip Soft Plate Systems and Metal Backplates.

Your choice as a diver is not critical because in-water the total weight difference is typically less than {4 lb}, so frequent flyers often choose aluminum over all other considerations when they want to travel as light as possible. For a more detailed discussion, see our tektip Aluminum vs. Stainless Hardware

About {25 lb | 10 kg} is the lift you need with your buoyancy aircell (called a 'wing') for single tank diving, assuming you are properly weighted with a modern cylinder. Manifolded doubles require about {45 lb | 20 kg} of lift. If you need more lift then you are diving a giant old Heiser/Beauchat cylinder or you are diving steel doubles with several stage bottles, otherwise you probably need to "get the lead out". These are just approximations because the cylinder sizes, types and configurations, not lift capacity and not body weight, is the best guide to selecting the correct wing. We have more information in our article Suggestions for Selecting a Wing.

NO, using a larger wing with a drysuit may even be counter productive! The wing lift is used only to counteract the weight of the cylinders & valves plus the backplate & harness. Of course most divers will also be carrying additional weight to compensate for the buoyancy of the drysuit, perhaps quite a lot more if wearing thick undergarments for diving in cold water. However, do not plan on using the wing as backup buoyancy in the event of a drysuit flood. Instead, the additional weight to compensate for the drysuit must be configured to be incrementally ditchable in the event of a drysuit failure.

Conversely, while some divers consider the drysuit to theoretically be backup buoyancy in the event of a wing failure, that's not best practice either. In reality, depending on their orientation in respect to the surface, many divers would find they have to so over inflate the drysuit to compensate that they lose mobility in their arms and may feel choked at their neck. For backup buoyancy in the event of a wing failure, we recommend selecting a dual bladder wing design.

Some wings offer the option of a "Remote Exhaust" (aka pull-to-dump) elbow or "Plain" elbow. The remote exhaust convenience feature is present on nearly all recreational sport BCD jackets, the plain elbow is most common on back inflation wings.

For experienced and technical divers, as a result of their often horizontal position in the water, they use the OPV pull at the bottom of the wing to release gas or hold their inflation assembly above the 'bubble' and press the oral inflate button to release gas. Many divers view the remote exhaust feature as an unnecessary feature that is just something that could fail and therefore prefer to use their skills to trade off the questionable convenience for certain reliability by selecting a plain elbow.

The standard corrugated hose on the inflation assembly is usually about 16-inches long. A few technical divers, especially cave divers, prefer a shorter corrugated hose to reduce the "danglies". Some physically very tall or large divers need a longer corrugated hose length and longer corrugated hoses are also usually found on BC integrated alternate second stage regulators.

The simple answer is "probably not". The STA is a product which predates modern backplate and wing designs that include pre-cut slots for cam straps. Using the straps threaded through the backplate snugs the tank and wing up very tight against the backplate and does not allow the tank to rock. Using an STA sets the tank farther away from the backplate and allows the tank to rock slightly by pivoting from side to side on the bolts. For more information read our article Single Tank Mounting with Backplates.

Assembly screws are also called "book screws" or "sex bolts", and are available in both metal and plastic versions. Years ago our suppliers used to include a metal set with their wings and later switched to a plastic set, but have not included either for a long time because assembly screws are often counterproductive.

The plastic assembly screws can be used to attach the wing directly to a hard metal backplate when rigged for a single tank without a single tank adapter. Note that this function is just cosmetic, omitting the assembly screws does not cause a problem. Without the assembly screws, when the BCD is taken off a single tank, the wing will hang loose on the cam straps.

The metal assembly screws can be used to attach accessories to the holes on edges of metal backplates, but in our opinion the plastic ones actually work better. Don't be concerned about the strength of plastic vs metal; the plastic version is plenty strong for these applications plus they are not subject to galvanic action and don't cause wear on materials rubbing against them.

Most technical diving aircells use a soft "crushproof" EPDM corrugated hose with excellent durability and strength in diving applications. The EPDM material contains a surfactant for injection mold release that exhibits a gradual "blooming" of a white haze on the surface of the hose as it dries following manufacturing. Unlike rubber, EPDM material does not oxidize and the presence of a white haze is not an indication of deterioration or use. We recommend allowing it to remain, but if the cosmetics are bothersome then it can be scrubbed off with ordinary soap, water and a cloth.

Unfortunately, there is no meaningful number we can use to describe the stiffness of our DGX Gears {2 in | 5 cm} harness webbing. The best answer we can give is that our webbing is what we believe to be the "correct amount" of compromise between flexibility and stiffness for the specific application of SCUBA diving BCD harnesses - stiffer than "seat-belt" webbing but less stiff than "tank-strap" webbing. The webbing may seem a little too stiff at first, but once wet and "broken-in" it will be the correct amount of stiffness to hold a shape and be comfortable.

Both are harness, backplate and wing type systems: The TransPac is a 'soft' plate using a semi rigid high-tech material. The TransPlate is fully rigid metal plate (your choice of aluminum or steel). With a properly adjusted harness, both are equally as stable. We are sometimes asked if the TransPac can have a plate "added"; the answer is no. While other brands do offer "hybrid" systems, because of the nature of the TransPac design combining hard and soft plates together wouldn't produce any benefit. The hybrid systems offered by other brands can best be thought of as a TransPlate with a lumbar backpad option.

We most often recommend the TransPac because it is always more comfortable and form fitting than the TransPlate. Even adding a lumbar backpad to the TransPlate will not make it as comfortable or form-fitting as the TransPac. If you want to add extra weight, choose the stainless steel TransPlate system. Most people diving double cylinders choose the TransPlate. Most people diving single cylinders choose the TransPac. Most people who dive drysuit exclusively choose TransPlate, most people who dive wetsuit exclusively choose TransPac.

The difference is primarily the fabric material of the outer shell and the warranty.

The EXP series wings have an outer fabric shell made of tough 1680 denier ballistic nylon. We stock the EXP wings in the black color, with the single tank wings available in five other colors and the classic doubles wings available in two other colors. EXP series wings feature a one year limited warranty.

The XT series outer fabric shell, built upon the SuperFabric® technology, is outstandingly rugged. Dive Rite's XT Armored wings have the durability of SuperFabric outer side with a 1000 denier Cordura® inner side to create an armor-clad shell that is impervious to damaging pinches, cuts and abrasions. The Dive Rite XT wings are available in solid black color and feature a LIFETIME LIMITED GUARANTEE against punctures and abrasion.

For more information visit Dive Rite Wings Overview.

The main difference is the Hydro Lite is a non-modular design with {30 lb | 13.6 kg} of lift and is appropriate for recreational single tank diving in warm water with aluminum {80 cu ft | 11L} and steel {100 cu ft | 12L} tanks or smaller. It is similar to a TransPac harness configured with a Travel wing, however the TransPac provides a completely modular design that allows changing wings as needed for diving with large single tanks, doubles or sidemount diving. If you are a technical diver or looking to do technical dives in the near future then the modular design of the TransPac provides a variety of configuration options.
The Nomad LS is strictly a sidemount only BC and is more appropriate for warmer water diving where the 35lbs of lift is adequate. The Nomad XT works better for colder environments when using it for sidemount when the diver is using steel tanks and/or larger amount of weight. The Nomad XT is also a modular system with the Transpac XT as the harness with a sidemount specific bladder. It can also be used as a single tank BC (adding cam straps) or doubles (adding stabilizer plates) as well.
Unfortunately, our answer regarding compatibility must be "we don't know" when we are not a service center for your equipment brand. We offer our generic service parts and tools for use only by qualified repair technicians who are able to determine compatibility for themselves using our descriptions and photographs. We do not recommend a trial and error repair strategy for life support equipment. The safe practice in circumstances of uncertainty is to contact the service department at the manufacturer. We especially recommend against DIY repairs on BC devices.
We don't offer replacement bladders and there is a good reason. Manufacturers frequently make changes to components in their wings, and there is no way to be sure that current bladders will be compatible with existing fabric shells, pull dumps, or inflation elbow fittings. We recommend that you directly contact the service department for the manufacturer of your BCD and arrange to return it to them for repair. For more detailed information, please read BCD Bladder Repairs
We do stock a few generic replacement parts such as hoses and O-rings, but in general our answer has to be "probably not" for most BC and regulator parts from these popular brands. We know it's frustrating; some dive equipment brands do not believe the consumer has the right to repair using concerns about liability or safety as their reason for prohibiting the retail sale of their branded individual replacement parts to consumers. The good news is that we agree the consumer has the right to repair and our Dive Gear Express policy is to sell individual parts for most brands we currently stock.