Wing lift with steel tanks

[utdivermatt]

But the only reason you have 17lbs of lead is that with all of your stuff on, it requires 17 extra pounds to hold you down. Where would you be in a situation where this requires much lift if you already have enough buoyancy to hold up that 17 lbs? I am not trying to sound stupid, but it seems like the amount of buoyancy is extreme.

 

[jepuskar]

I just wanted to update everyone since some of you expressed concerns about me not being able to surface because of lack of wing lift. I know that would break several hearts if I became a permanent fixture at the bottom of some mud hole...anywho...

I just received the Halcyon Eclipse 40# wing. It is a little bigger thn anticipated, but then again..since when does size matter?

 

[Don Burke]

But the only reason you have 17lbs of lead is that with all of your stuff on, it requires 17 extra pounds to hold you down. Where would you be in a situation where this requires much lift if you already have enough buoyancy to hold up that 17 lbs? I am not trying to sound stupid, but it seems like the amount of buoyancy is extreme.

Figure about six pounds of gas in an AL80, about twelve in a steel 125 or doubled AL80s. A thick wetsuit can easily be over twenty-five pounds positive at the surface and lose nearly three quarters of that at one hundred feet. That is about thirty pounds of buoyancy change that the BC needs to compensate for.

With the doubled 100s in the original question, there is about sixteen pounds of gas to be accounted for. While the diver is going to be using a drysuit, there will be compressible gear involved (hood, gloves) that will make the total change more than twenty pounds. If some water gets in the suit, at least some of it will be replacing air inside the suit (some of it will just bulge the suit and have no net change in buoyancy), and could easily run ten pounds. With some restriction on the wing, not all of the advertised lift will be there. Overall, I would want around a forty pound wing to dive this rig. Sixty would be a bit much, but not a crisis.