Buoyancy Control Devices (BCs) FAQ
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.
There is no standard but too long can cause just as many problems as too short. Most jacket style BCD's have a 19-inch to 22-inch corrugated inflation assembly, and therefore require a 26-inch to 28-inch low-pressure inflator hose. Similarly, the convention for most back inflation wings is a 16-inch corrugated inflation assembly and the usual low-pressure hose is 22-inches long.
Some of this is further affected by your preferred size tank and mounting height along with the design of the first stage body, fixed or swivel, plus the choice of orientation and installation port such as side or 5th port. If you are using a BC integrated second stage, selecting the appropriate length can be even more critical. Often the correct length hose will appear to be too short while your assembled rig is sitting in the tank rack, but then once you don your setup and make your water entry everything will lay correctly. Ultimately, the best answer is determined by in-water trialing to find what produces the most streamlined configuration specifically for you.
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.
With a remote exhaust elbow, a cable runs from the inflator inside the corrugated hose up to the remote exhaust dump valve. To exhaust gas from the air cell, you need only tug gently on the inflator. This is the preferred option for open water divers as this feature works best when in a more upright position and offers an option for dumping gas during ascent at the end of your dive.
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 sometimes also seen 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 when these proved problematic they 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.
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.