Spare Air on deep but no deco dives??

[ReadyDiverOne]

I’m curious to get peoples’ views on this. I’ve never bought or used a Spare Air or similar extra bottle, what do people think about them? I’ve seen mixed reactions, including that if you’re really out of air at depth (say 110 or deeper) they don’t provide enough air to get to the surface without doing a CESA in any event. I’ve never (yet) had an issue or been in a dive where someone had an issue, and I carefully monitor my gas both with an air integrated Suunto and of course an analog SPG, and I stay near (ok, pretty near) to my buddy. But I guess you never know. So let me know what you think. Again, I stress that this is strictly limited to no deco diving. Oh, and there is almost always either a tank or regulator with air hanging from the boat at 15 feet.

 

[RockiesFan]

Your milage may vary of course, but just go with a pony bottle as opposed to a spare air.

 

[rsingler]

I agree with @psibar . A Spare Air is false security. With only 1.7 or 3 cu ft, do the math: common air consumptions are 0.5-0.8 cu ft/min.
So a 1 cu ft/min slightly panicked OOA diver at 99 feet (4 atm). That means between 99 feet and the surface with no safety stop, your average depth is EDIT: 2.5 atm. Therefore 2.5 cu ft/min average consumption from a tiny Spare Air gives you EDIT: 41 sec or 72 sec to go 100 feet. Ascent rate MUCH faster than 30 fpm.
Like he said, even a tiny 6 cu ft pony will do better than that, and a 9 or 12 is still very easy to clip on.

 

[Aviyes]

This breaks it down pretty well. Is Spare Air Enough?

 

[RyanT]

I tried a spare air many, many moons ago. In addition to not having enough gas, you are asking a lot for a regulator to integrate the jobs of both a first and second stage together in a small package. The one I had leaked on a regular basis, probably just a function of the design. Do yourself a favor, get a small pony (a 19 cf is actually really easy to sling) and standard regulator.

 

[ScubaJCBS]

I agree with the above. I normally sling a 13 which most see as not enough. But I'm thinking of going to a 19 because there's not a lot of felt difference to me between the two. I run pro k valves and use my sidemount din regs because one I haver them and two the profile is alot small than yoke. I think you can also what if yourself into a submarine just do the best you can and keep watching your spg!

 

[Bob DBF]

The one I had leaked on a regular basis, probably just a function of the design.

Mine leaked as well, I found that any crud that got into the reg from my shore dives would cause the problem until I disassembled the reg and cleaned it. I figured it was more of a PITA than it was worth.

Do yourself a favor, get a small pony (a 19 cf is actually really easy to sling) and standard regulator.

That's what I finally did, the good news was that I had the parts to make one up so I just had to buy the bottle.

A Spare Air is false security.

Depends on what you expect out of it. I just figured an extra breath during a csea was better than none, and a bottle on me would be better than one left on the beach because it was a hassle.

If one expects it to magicly give more air than it holds, then that is a false sense of security.



Bob

 

[drrich2]

I've seen complaints of slow gas leaks before, so when I bought one, I had the vendor add the button gauge so I could see what pressure remained. And mine holds pressure well.

It's got its limitations, and you should know them, but in some cases where I wouldn't bother with a standard pony, it can be better than nothing. I've got a 30-cf pony and a Spare Air 3.

Richard.

 

[mainedvr]

I tried a spare air, did not last long at all and they are not cheap, better off getting a bottle the size you need 19 or 40 or whatever or a pony set up what ever fits you needs and use that at least you will have a meaningful amount of reserve gas if needed. Don't get me wrong if I had an issue and someone stuck a spare air in my face to help me I would take it but to plan on using it I would not.

 

[mainedvr]

I’m curious to get peoples’ views on this. I’ve never bought or used a Spare Air or similar extra bottle, what do people think about them? I’ve seen mixed reactions, including that if you’re really out of air at depth (say 110 or deeper) they don’t provide enough air to get to the surface without doing a CESA in any event. I’ve never (yet) had an issue or been in a dive where someone had an issue, and I carefully monitor my gas both with an air integrated Suunto and of course an analog SPG, and I stay near (ok, pretty near) to my buddy. But I guess you never know. So let me know what you think. Again, I stress that this is strictly limited to no deco diving. Oh, and there is almost always either a tank or regulator with air hanging from the boat at 15 feet.

Good question, I posted another response but want to point out if you have an issue there is a chance you won't make it to the line to get on the hanging reg, so as my other response noted I would not want to rely on it when there are other ways with more air. Just my opinion