Lift bag as redundant boyancy

[mainedvr]

Hey,

Question is for those of you carry a lift bag for redundant boyancy in case of major failure can you answer the below questions

How much lift?
What style (open bottom or closed)? Pro's Con's
Do you carry in a back pad pocket or other methods of stowing?
Do you carry it ready to go on a spool or have them seperate till needed? Pro's Con's


Thanks

 

[jgttrey]

I carry a DSMB for its own sake but it was a required skill to use it as redundant buoyancy during training.

If one is properly weighted, you probably don't need much lift. I think a 6" "normal" SMB is prob. 30+ lbs positive when inflated, which is way more than I would ever need. But, you can just do the math I suppose and figure out what is enough. Personally, if I was in some configuration that for whatever reason I couldn't get balanced well and needed tons of redundant lift, I'd get a second bladder rather than rely on a lift bag or SMB.

I prefer open bottom because it gives me an additional way to fill and if I'm diving OC recreational, it's easier to use a reg than unplug the low pressure inflator hose. If diving in any other configuration, I usually have an LPI handy on another bottle that makes it easy to fill the SMB.

I carry bungeed to the bottom of my backplate. I keep it rigged with the spool because it's much faster to deploy for it's primary purpose, as a marker. That's the pro. The cons are: (1) if you need the spool for something else (which you shouldn't, just carry another) you have to remove from the SMB; (2) if you rig in a way that allows the spool to detach accidently, you end up with a 200' tail hanging off your SMB (but this can be solved by rigging correctly); the spool is dangling off the bottom and sometimes gets in the way when I set my gear down or rig up, but it's no big deal.