Since stage tanks are usually (always?) aluminum tanks, they will be positive when empty. This affects the balanced weighting of the entire rig. I have heard that stage tanks are not calculated as part of your weighting, since you need to be balanced in the event that you drop/stage/leave tanks. But does that also hold true for the positive buoyancy of empty stage bottles?
Having let's say two more or less empty AL80s (bottom stage + deco stage) when you arrive at your final deco stop would provide quite a bit of positive buoyancy, that you need to deal with. Or is there something I'm missing? I realize there will usually be gas reserves in play, but in the worst case scenario with gas sharing, I assume you wouldn't want to struggle with being too light on top off an already sticky situation.
TLDR:
Do you adjust your weighting to account for positive buoyancy of empty stages. If so, how? Do you just add the weights you estimate for the buoyancy characteristics of the stage bottle? Or do you do a weight check with each configuration?
PS.
I assume this will be covered in a tech class, but I like to get a head start on the topics covered before I take a class.
Having let's say two more or less empty AL80s (bottom stage + deco stage) when you arrive at your final deco stop would provide quite a bit of positive buoyancy, that you need to deal with. Or is there something I'm missing? I realize there will usually be gas reserves in play, but in the worst case scenario with gas sharing, I assume you wouldn't want to struggle with being too light on top off an already sticky situation.
TLDR:
Do you adjust your weighting to account for positive buoyancy of empty stages. If so, how? Do you just add the weights you estimate for the buoyancy characteristics of the stage bottle? Or do you do a weight check with each configuration?
PS.
I assume this will be covered in a tech class, but I like to get a head start on the topics covered before I take a class.
