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Bladder Bcd

What does pounds of lift mean on a diving wing bladder bcd?

I am looking at purchasing a wing bcd for diving. Some have 30 pounds of lift and some have 100 pounds of lift. What do these numbers mean and what kind of diving are they most suitable for.

I weigh 160 lbs and qualified to dive 40 meters. However, in the future I would like to take up technical diving. What wing and pounds of lift would be best suited for me?

In a nut shell, that's how much weight that wing is capable of holding at the surface when it's fully inflated and laid out flat. It's not the same as true lift, which is the number a lot of BC manufacturers are starting to quote. Lift can differ by almost 20% over true lift due to factors like bend in the wing, the archimedes effect on the weights being used to come up with the lift number in the test and the fact that the BC can actually only need an ounce extra to sink, yet weights normally come in a minimum one pound piece. Sometimes two pounds. Right there, for an example, you've got an almost two pound error induced in the wing's capacity.
In the newer true lift rating system, the lift is tested by assembling an entire rig, ballasting the rig to get it just submerged when inflated and then hooking it to a weight measuring device. The rigs weight is measured both fully inflated and fully deflated. The difference is the true lift number.
Forget how much you weigh...you weigh next to nothing. Remember, you are at eyeball height in the water, most of the air out of your BC to be considered trimmed out. It's only when you punch past that magic 15 ft that the BC really starts to play a role in providing you with lift
Right now, if you're a warm water diver, you'll only need a smaller wing. When you go tech and start lugging doubles or diving cold, that's when you'll want to step it up since you're wearing additional pounds, not just in tanks ( and they may be steel to boot) but in ballast as well to offset the extra thermal protection buoyancy. It's pointless getting the larger wing now if you're diving a single. You'll just get tank wrap if that wing even lets you mount it single without tank bands and back plate anyway. Neither my OMS nor my Dive Rite allow a single on the large lift nor a set of doubles on the travel wings. Gotta use the right wing for the job / rig configuration.