Spare air - or not?

[MaxBottomtime]

I've run tanks down to nothing on purpose a few times in water I could stand up in. You can feel resistance buiding with each breath as the tank drains. Usually four or five breaths before you suck on a brick wall. You wouldn't have as many breaths at depth, but there is no reason to breathe a tank low at depth. The best piece of modern scuba gear is the spg. If you look at it once in awhile, Spare Air versus pony bottle threads become meaningless.

 

[TSandM]

Andy has a really good point there, which should be reemphasized.

The only real emergency on scuba is being out of gas; everything else is an inconvenience. Panic is what kills divers, and one of the goals of any problem solution in diving should be to reduce stress. The BEST solution to being out of gas is not to do it, which means gas planning and maintaining adequate reserves. The second best solution is a capable, practiced buddy who has maintained adequate reserves. The third option (and remember, this should ONLY need to be employed in case of catastrophic gas loss or shutoff, both of which are rare) is a completely independent, secondary gas supply -- and this should have two characteristics. One, it should be extremely easy to access, and two, it should be large enough that the diver can take a couple of deep breaths and relax, and then proceed with the rest of the solution in a methodical and unhurried way. A Spare Air just doesn't meet those criteria.

 

[DandyDon]

Question for anyone that can answer this.

What does it feel like to actually run out of air? Do you have a nice full breath and then the next there is nothing or can you began to feel like you are having to "suck harder" on the last few breaths thus letting you know you have a real problem?

Thanks.

:laughing: It's probably a good idea to actually practice this but having your buddy turn off your valve is not really the same. I guess it'd be fool hardy to dive to 60 ft with a 500# tank and wait for it tho. :shocked2:

From my limited & stupid experience, after arriving on Coz the night before too late to get my pony sent to the fill shack, then making a group dive to 50 ft, incurring one little problem after another, finally getting everything sorted out and my camera aimed, but failing to check my spg, :silly: I felt a hard drag and thought "Oh caca!" I actually had done this once before several years ago and remembered that stupid feeling. :blush: I check my spg, thought "Damn! Screw this!" waived bye to the DM I was buddied with but too far from (I think I was too embarrassed; see "Pride cometh before a fall"), and headed up on my unplanned CESA.

To summarize the rest of that story, I did keep my reg in my mouth at least, exhaling, ascending slowly enough that I ran out of lung air, stopped to suck a breath of recovered air from the tank - something to remember if you do use a SA for a fast CESA, then continued with my slow exhale and up, surfacing with enough left to inflate my BC and blow an inline whistle at the boat. One thing I did not think of and should have done is remove at least one weight pocket to hold onto so if I badly screwed up and passed out I would at least drop it and float to the surface. A drowned diver on top is easier to find and try to revive than one below. What I really should have done was skip the morning boat, get my head & gear better organized to dive safer, and wait for my pony - but there's my dumb story.

So, don't screw up, but if you do - have your pony ready, or a SA you can rapidly deploy.

 

[WetBoy101]

Will some one volunteer to take some spare air bottles to various depths and see how many breaths they get?

 

[*dave*]

So, don't screw up, but if you do - have your pony ready, or a SA you can rapidly deploy.

and hold onto one of your weight pouches so they can find the body when you pass out


Jesus, Don....

 

[DandyDon]

and hold onto one of your weight pouches so they can find the body when you pass out


Jesus, Don....

I know, I should hide my screw ups like most rather than admitting them in public - but that suggestion came from Ken Kurtis‎, the LA Instructor who works closely with the coroners office on county scuba deaths there - and it's a good one, aside from the fact that no one should ever run OOA, but it happens.

 

[*dave*]

Planning your dive around advice from a coroner might be a great way to assure your body will be found, but it seems like shoring up the parts of your plan that will actually keep you alive would be time better spent, no?

 

[DandyDon]

Planning your dive around advice from a coroner might be a great way to assure your body will be found, but it seems like shoring up the parts of your plan that will actually keep you alive would be time better spent, no?

Yeah yeah, fine - you answer that question. I am deleting my account. Bye

Question for anyone that can answer this.

What does it feel like to actually run out of air? Do you have a nice full breath and then the next there is nothing or can you began to feel like you are having to "suck harder" on the last few breaths thus letting you know you have a real problem?

Thanks.

 

[doctormike]

Planning your dive around advice from a coroner might be a great way to assure your body will be found, but it seems like shoring up the parts of your plan that will actually keep you alive would be time better spent, no?

No, I think you are missing Don's point... holding the weight in your hand ensures two things -

1) that you won't have an uncontrolled ascent (admittedly not much of an issue once you are doing a CESA)

2) that if you pass out (but don't die), you will drop the weight on the surface, so that you can be rescued!

And a coroner probably has some good insights into what kills people, he might be just the guy to keep you alive!

Or maybe I missed the joke?

 

[DandyDon]

No, I think you are missing Don's point... holding the weight in your hand ensures two things -

1) that you won't have an uncontrolled ascent (admittedly not much of an issue once you are doing a CESA)

2) that if you pass out (but don't die), you will drop the weight on the surface, so that you can be rescued!

And a coroner probably has some good insights into what kills people, he might be just the guy to keep you alive!

Or maybe I missed the joke?

No, that's about it, or if you pass out before surfacing, at least you'll bob to the surface for possible rescue. And Ken is an Instructor, not the coroner.