Why Steel Doubles?

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Well you don't count deco or stage tanks as part of your ballast because they are indeed ditchable. But you're completely correct, even double 100's carry 16lbs of gas. In my 130's I'd be anywhere from 25-40lbs negative at depth depending on how full/empty my tanks are.
 
Well you don't count deco or stage tanks as part of your ballast because they are indeed ditchable. But you're completely correct, even double 100's carry 16lbs of gas.

Not a ballast :) but a counter ballast. I mean if you plan to lunch them up at the end of the dive then yeah you do not have to count them in, but say if you do not plan to get rid of them you need to compensate them being floaty. Say in worst case scenario if you share your gas with your buddy and sucked almost all the gas and the stages/deco bottles you have to lunch them up or you can become too positive , am I missing anything ? :coffee:
 
While thinking about and after you posted the 10lb being the average (or limit) that can be brought up it I started to understand why they recommend AL80 :D It's just 150 cuf that you can sweem up :D So it's not a matter of the material but the volume :D
 
Not a ballast :) but a counter ballast. I mean if you plan to lunch them up at the end of the dive then yeah you do not have to count them in, but say if you do not plan to get rid of them you need to compensate them being floaty. Say in worst case scenario if you share your gas with your buddy and sucked almost all the gas and the stages/deco bottles you have to lunch them up or you can become too positive , am I missing anything ? :coffee:

I know when you talk about an AL40 as a deco bottle you don't change your weighting for it. It's pretty much neutral to slightly negative. If a problem arose where you needed to swim your rig up you could always ditch the deco bottle. I don't think I'd be too worried about going up too fast if I was in a situation where I had a wing failure and no redundant buoyancy. I'd rather be bent than dead.
 
I know when you talk about an AL40 as a deco bottle you don't change your weighting for it. It's pretty much neutral to slightly negative. If a problem arose where you needed to swim your rig up you could always ditch the deco bottle. I don't think I'd be too worried about going up too fast if I was in a situation where I had a wing failure and no redundant buoyancy. I'd rather be bent than dead.

Yeah I got what you were saying after thinking a bit. In worst case scenario (All bottles are full) they are negative and can be ditched if necessary.
 
with double AL80s I'd be swimming up around 10lbs if failure happened with full tanks. The more gas I use the lighter the tanks will be the less I have to swim up. Luxfer AL80's are -1.4 full and +4.4 empty
 
with double AL80s I'd be swimming up around 10lbs if failure happened with full tanks. The more gas I use the lighter the tanks will be the less I have to swim up. Luxfer AL80's are -1.4 full and +4.4 empty

You are such a wealth of internet bookmarked knowledge...
 
I use XS Scuba weight pouches on my cambands for additional weight with singles. pvcole, I'd be happy to go diving with you and show you my setup some time.
 
https://www.shearwater.com/products/peregrine/

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