Choosing a Backplate and Wing: Plate, Wing Lift, Harness

A backplate and wing has three parts: the plate, the wing and the harness. Each is a separate decision, which is the point: you can change one without replacing the others. It also means there are a few choices to get right.

Quick decision table

Gardner Underwater doesn't pair steel cylinders with wetsuits, whatever the plate.

Steel or aluminum plate?

Stainless steel plates are heavier, typically around 5 to 6 pounds. In cold water, with a thick wetsuit or a drysuit, that weight replaces lead you'd otherwise carry on a belt, and it sits high and centered on your back. It moves ballast rather than reducing the total you need, so keep the ditchable weight your balanced-rig plan calls for. See What Is a Balanced Rig.

Aluminum plates are light. They suit warm water, thin suits and travel, where you don't need the extra weight and don't want to carry it in your luggage.

If you dive both in cold water at home and warm water on trips, a steel plate at home and an aluminum plate for travel is a common combination. The harness moves between them.

How much wing lift do you need?

Enough to do two jobs, with a margin:

1. Float your full rig at the surface, with full cylinders.
2. Balance the full rig at depth. Account for gas weight, suit compression and other equipment buoyancy. A wetsuit loses lift as it compresses, and the wing must be sized for the actual negative load.

Then stop. The temptation is to buy a big wing "just in case," but an oversized wing traps air in its corners, is harder to vent and adds drag. Size it to the rig you actually dive, not the biggest dive you can imagine.

Single-tank and doubles wings are different products. One wing rarely does both well.

What harness?

A DIR harness is simple on purpose:

• One continuous piece of 2-inch webbing, threaded through the plate.
• A single buckle at the waist.
• A crotch strap, so the plate can't ride up.
• D-rings at the chest and on the left side of the waist belt. Gardner Underwater's list calls for adjustable chest D-rings and two adjustable D-rings on the left hip.
• No quick releases and no padding.

It's adjusted once to your body and your suit, and checked again whenever your suit changes. Snug enough to hold the plate in place, loose enough to reach your valves and breathe deeply.

Other details worth getting right

• Inflator on the left. The wing's inflator hose comes over your left shoulder, matching the standard configuration.
• A single-tank adapter if you dive a single cylinder on a flat plate, unless your wing is designed to hold one directly.
• Cam bands that hold the cylinder high enough to reach the valve, without it hitting your head.
• Nothing extra. No pockets on the wing, no D-rings you won't use.

Try before you buy

The best way to choose is to dive a configured rig with someone who can adjust it on you. Gardner Underwater's equipment list specifies a backplate, harness and appropriate wing for backmount training, and training is the easiest place to try combinations before you spend money.

For how the rig fits into the rest of the configuration, see DIR Gear Configuration, Piece by Piece. For whether to start with one at all, see Is a Backplate and Wing Good for Beginners? To try before you buy, you can rent a DIR singles or doubles backplate and wing through our shop.