Backplate and wing

Backplate and wing

A stainless steel backplate, wing and manifolded twinset
Uses	Scuba harness and buoyancy compensator
Related items	Buoyancy compensator (diving)

A backplate and wing (often abbreviated as BP&W or BP/W) is a type of scuba harness with an attached buoyancy compensation device (BCD) which establishes neutral buoyancy underwater and positive buoyancy on the surface. Unlike most other BCDs, the backplate and wing is a modular system, in that it consists of separable components. The core components of this system are:

The basic harness comprises two lengths of 2" (50mm) webbing: One is woven through the slots in the backplate to form closed shoulder loops and an open waist strap, with a weightbelt-type lever action buckle for securing the waist strap,

The second section of webbing forms a crotch strap, running from the bottom of the backplate, between the diver’s legs, and up to the waist strap, which would be passed through a loop at the front end of the crotch strap. This harness is sometimes referred to as a one-piece harness, due to the shoulder and waist straps being made from a single piece of webbing.

The harness is usually fitted with stainless steel D-rings secured by stainless steel "sliders", small slotted plates which hold their position by friction. A loop of elastic cord is normally attached at the same place as the left shoulder D-ring, to secure the wing’s inflator hose.

This arrangement is extremely rugged, reliable and hard-wearing.

This form of harness may be adjusted to fit different builds of diver by shortening the webbing used to tighten the harness, or installing a new longer section of webbing to loosen the harness. Once adjusted, some flexibility is still allowed by positioning the buckle, which can change the effective length of the waist strap depending on where it is secured.

The harness webbing can be replaced at home with no special tools when the webbing wears through or is damaged, and other components can be easily replaced. This makes this style of harness very economical over the long term.

Many variations to this basic harness are used, and these may include:

Some manufacturers offer alternative harnesses, often marketed as “deluxe” options, which may include the above variations.

Omitting the buoyancy bladder reduces the setup to a plain backpack harness if the breathing set needs to be used on land. However, the standard scuba backplate is ergonomically unsuited to this function.

The backplate is usually made from a single piece of stainless steel or anodised aluminium, bent along four lines to form a channel running vertically down the center. The plate is about 15” (38 cm) long and 10” (25 cm) wide. There are two slots near each of the shoulders and hips, where the harness passes through, and another slot at the bottom of the plate where the crotch strap attaches. There is also one or more pairs of holes in the channel to be used for cylinder attachment; the holes of each pair are 11” apart.