Spare Air - Sorry!

[UaVaj]

(i) unbalances
(ii) cant check it for leaks/turn it on/off
(iii) people breathe from wrong reg and end up dead
(iv) heavy on back on land
(v) cant be handed off to someone else or a boat to get back onboard
(vi) 2 more hoses coming in front of you so chance of checking wrong gauge and/or breathing wrong reg exists..and it does happen.

I cant see a single advantage to back mounting.

Are you for real?

(i) shift the weight you carrying to one side to balance out.
(ii) mount it upside down. easily reach the valve. as for leaks - my hoseless dive computer monitors the gas pressure.
(iii) those folks should not be diving at all. perhap they should give up scuba all together.
(iv) your point is? rather be on your back or sling. weight the same.
(v) won't argue with you here. but my pony is for me. not someone else. everyone should have their own bail out bottle.
(vi) only hose from the pony coming up to the front is the reg itself. no mistake in breathing the wrong regulator. as for gas pressure hose. it is hoseless.

biggest advantage. both your hand and arm are 100% free. base on your answers - obviously you do not hunt underwater. hence you do not know the difference?

 

[Delta_P]

My thoughts are best summed up by the term "Belt and Braces" I guess, do I get nervous about diving - yes I/we do, I assume most divers share some anxiety!

I'm curious Ralph - what sort of failure are you imagining here?

You've mentioned equipment failure. Are you imagining your regulator suddenly locking up and not feeding you air?

Something that hasn't been mentioned yet is that Spare Airs are not "set and forget" devices. They can leak down between dives so they must be checked before each and every jump. I've also caught them leaking during a dive.

 

[DevonDiver]

Something that hasn't been mentioned yet is that Spare Airs are not "set and forget" devices. They can leak down between dives so they must be checked before each and every jump. I've also caught them leaking during a dive.

Wow...you must have been quick to spot that Not much air to leak.....

 

[Delta_P]

Wow...you must have been quick to spot that Not much air to leak.....

Yeah. It was o.k. though - I still had my lucky rabbit's foot backup.

 

[RalphPorter]

I'm curious Ralph - what sort of failure are you imagining here?

You've mentioned equipment failure. Are you imagining your regulator suddenly locking up and not feeding you air?

Something that hasn't been mentioned yet is that Spare Airs are not "set and forget" devices. They can leak down between dives so they must be checked before each and every jump. I've also caught them leaking during a dive.

Well I'll be honest and say I'm not sure what the situation might be but I'm pretty sure there must be potential situations, I wear my seatbelt when I drive because I don't know if / when or why I might have an accident if I drive carefully then in theory it won't be my fault. Are you simply suggesting that if I dive with my buddy the way we should that there are no conceivable circumstances where the extra air source would be employed, is that also true if I'm talking about a 6cu or 13cu bail out bottle...

Take your point about maintenance and reliability - if they're prone to problems then that would be enough to dissuade me at least from that brand but not neccesarilly the principle, still swaying from side to side on that and trying to organise the arguments for and against into relevance for the diving I do - I'm pretty convinced now that they're of little use for dives deeper than 60' and even for dives at that depth or less the 6cu option looks like the minimum.

 

[TSandM]

Ralph, a friend of mine talks about "Little House on the Prairie" thinking . . . you can certainly posit a situation where you could end up out of gas and separated from your buddy, and too deep to CESA. But the agency with which I have trained says, "We plan for a single major failure," and that has always seemed reasonable to me. In your case, someone could have a freeflow or a burst hose, but if you are close to your buddy, and everyone is maintaining gas reserves, and has practiced air-sharing, that problem is quickly solved. If you get separated from your buddy, you have substantial gas reserves to deal with being anxious (because you're carrying enough for BOTH of you, right?) and after a short search, you abort the dive and head for the gas tank in the sky.

All of us have to decide what we think are reasonable degrees of redundancy and insurance for the diving we do. For me, so long as I am diving with someone who I can trust to watch their gas, and whose skills in emergency procedures I can predict to be reliable (and both things are certainly within your control as a couple) then my spare gas is on my buddy's back. When I dive with people I don't know, I either keep the dive shallow enough that I'm not worried about redundancy, or I dive double tanks. If you frequently find yourself diving with unknown folk, I don't blame you for wanting your own self-rescue -- but make it a useful one. There is NOTHING worse than a strategy that makes you FEEL secure, but doesn't work when it's required.

 

[TSandM]

Ralph, a friend of mine talks about "Little House on the Prairie" thinking . . . you can certainly posit a situation where you could end up out of gas and separated from your buddy, and too deep to CESA. But the agency with which I have trained says, "We plan for a single major failure," and that has always seemed reasonable to me. In your case, someone could have a freeflow or a burst hose, but if you are close to your buddy, and everyone is maintaining gas reserves, and has practiced air-sharing, that problem is quickly solved. If you get separated from your buddy, you have substantial gas reserves to deal with being anxious (because you're carrying enough for BOTH of you, right?) and after a short search, you abort the dive and head for the gas tank in the sky.

All of us have to decide what we think are reasonable degrees of redundancy and insurance for the diving we do. For me, so long as I am diving with someone who I can trust to watch their gas, and whose skills in emergency procedures I can predict to be reliable (and both things are certainly within your control as a couple) then my spare gas is on my buddy's back. When I dive with people I don't know, I either keep the dive shallow enough that I'm not worried about redundancy, or I dive double tanks. If you frequently find yourself diving with unknown folk, I don't blame you for wanting your own self-rescue -- but make it a useful one. There is NOTHING worse than a strategy that makes you FEEL secure, but doesn't work when it's required.

 

[diver_doug]

Even at 60ft you probably won't even be able to do a complete safety stop with the Spare Air...spare air will basically get you to the surface and that's about it. Also, if you're in a kelp bed, near boats, etc. you may want to swim to out of the area you're in before surfacing...probably won't be able to do much swimming with 3cuft. Like others have said, a pony is best and won't cost you much more than a Spare Air...I got a 19cuft/aqualung calypso reg/pony tamer for $320.

 

[RalphPorter]

Ralph, a friend of mine talks about "Little House on the Prairie" thinking . . . you can certainly posit a situation where you could end up out of gas and separated from your buddy, and too deep to CESA. But the agency with which I have trained says, "We plan for a single major failure," and that has always seemed reasonable to me. In your case, someone could have a freeflow or a burst hose, but if you are close to your buddy, and everyone is maintaining gas reserves, and has practiced air-sharing, that problem is quickly solved. If you get separated from your buddy, you have substantial gas reserves to deal with being anxious (because you're carrying enough for BOTH of you, right?) and after a short search, you abort the dive and head for the gas tank in the sky.

All of us have to decide what we think are reasonable degrees of redundancy and insurance for the diving we do. For me, so long as I am diving with someone who I can trust to watch their gas, and whose skills in emergency procedures I can predict to be reliable (and both things are certainly within your control as a couple) then my spare gas is on my buddy's back. When I dive with people I don't know, I either keep the dive shallow enough that I'm not worried about redundancy, or I dive double tanks. If you frequently find yourself diving with unknown folk, I don't blame you for wanting your own self-rescue -- but make it a useful one. There is NOTHING worse than a strategy that makes you FEEL secure, but doesn't work when it's required.

Hi, Just to reiterate I only dive with my regular buddy and we do regularly practice OOA drills (sharing air) and that is always going to be our immediate plan of action in such a situation, we also currently dive to a 60' limit and definately avoid all overheads. I think there are two pertinent questions in context of this for me having digested all this thread:

1) Is there any need at all for personal redundancy for this type of diving.

2) If the answer to the above is yes and let's say because of air travel weight, comfort, convenience my buddies lower back problems, the shore entries / exits we do etc that a 6cu Zeagle is as large as I'd personally go at the stage I'm at, am I better with it or without it.

When you say doesn't work do you mean I've not maintained it / switched it on etc or that's it's just not fit for purpose?

 

[GrumpyOldGuy]

Ralph,

The decision to use a redundant air source is a personal one you should base on your dive environment. The best system is often not practical, there are trade offs to consider and no matter what you decide, some people will think it is wrong.

1) Do you need a redundant system for your diving?

In my case normal dive buddies are my sons (similar to a spouse in trust level). The tend to stay close and watch their SPG and follow a basic gas plan. The can and will screw up, but they have the basics down solid in these areas. We tend to stray a bit deeper (80').

The redundant air system are typically left at home with them as the buddy system is better in this case. Not just to save my butt, but it makes me feel better as a dad to be close enough to assist should they get in trouble, I assume you feel the same about your spouse.

2) If you need one, is the 6cu ft system big enough to be worthwhile?

I have a similar one of the same size (H2Odessy with a hose) that I use on occasion when solo diving / travel diving. Since is has 2x the air, it actually has enough capacity to make a normal ascent from the depth you dive at. In a non-stressed situation, you can even do a safety stop.

In a narrow range of dives, I do feel it is worthwhile. I have practiced with it from 80' many times and it works just fine. It is not a general piece of safety gear though and in your case (buddy=spouse and buddy=bad back and depth <60) I would put off purchase.

Whatever you do, maintain you basic skills and dive safe