The great Spare Air / SpareAir topic

[Sideband]

I wouldn't hold my breath waiting for someone to tell you they even like SpareAir. From reading a recent thread on it, the general concensus was that they are not big enough for anything deeper than about 60 fsw. I believe "spare death" was a common term used in reference to them. Common thoughts were that they added a false sense of security.
The thread I'm talking about was someone asking about the proper use of one in an ooa situation at 130 or so feet.
Here is a link to that thread.
http://www.scubaboard.com/t7997.html
Interesting reading. I pretty much made up my mind on the topic.

Take care
Joe

 

[Otter]

You really need to do the math and figure out, based upon your diving style and profile, how much air you will need.

A number that is often used (probably because it makes the arithmetic easier) is that a paniced diver could have a SAC rate of 1 cu ft / min (or possibly even more). So if you are at 99' (4 ATMs), you would use 4 cu ft of air per min or on a ascent an average of 2 cu ft /min...and that excludes a safety stop. Factor in a reasonable ascent rate of 3 mins (30 ft / min) and a safety stop and you can see that even the 3 cu ft is insufficient. I am not going into all the details, but hopefully you get the idea of how to go about calculating what you need.

 

[tangfish]

I'm also starting to buy the arguments put forth by a lot of these people who hate spare air. But isn't there something to be said for a situation where someone is low on air and has enough to ascend but not enough to complete the safety stop? Could Spare Air not be used in such a situation? And don't give me the DIR bull of "you should never have run so low on air in the first place", because sometimes....it just happens.

 

[JeffG]

I'm also starting to buy the arguments put forth by a lot of these people who hate spare air. But isn't there something to be said for a situation where someone is low on air and has enough to ascend but not enough to complete the safety stop? Could Spare Air not be used in such a situation? And don't give me the DIR bull of "you should never have run so low on air in the first place", because sometimes....it just happens.

Get the 1.7 Nitrox version

 

[Sideband]

I'm also starting to buy the arguments put forth by a lot of these people who hate spare air. But isn't there something to be said for a situation where someone is low on air and has enough to ascend but not enough to complete the safety stop? Could Spare Air not be used in such a situation? And don't give me the DIR bull of "you should never have run so low on air in the first place", because sometimes....it just happens.

Probably not what you are looking for, but you are free to ignore it. I'm mostly addressing the last sentence.

That is that false sense of security they were talking about.
Sure it 'could' be used there. Air is air.
Share air from your buddy at the safety stop.
You BOTH should not have run that low on air. One of you, maybe, and the buddy that didn't run low gets to lecture the other about risking HIS life by being careless. You both were supposed to have enough air to get the other to the surface too. If both run low then it's time to review the plan to see where things went wrong.
Maybe I just had a really good instructor that made this a very serious point, but I don't think it's a DIR thing. It's being a responsible and dependable dive buddy. IMO, unless there was a malfunction that caused a sudden loss of air it didn't "just happen". The diver let it happen. Have a lot of divers had the experience? Yes. Does that make them any less responsible for it? No.
I may have some strong opinions on this for a new diver but I would be really ticked at a buddy that did that to me and would understand if they didn't dive with me again if I did it to them.

Joe

 

[Isaac-1]

After reading all these messages from people that say they would not use a spare-air, I would love to be on a dive with them when they ran into an out of air situation, so I could offer them my spare air and they could refuse to use it. Having said that I carry a 2.7 cu ft. spare air for my own peace of mind, as you never know what may happen to your primary air supply, the spare air gives me the option of more comfortably getting to my buddy, surfacing, etc. than no redundent air source does. A ponny bottle simply is not practical much of the time, and has its own drawbacks in terms of bulk, snag hazzard, etc.I have tested it from various depths numerous times, and I know that I can make a controled ascent from over 100 ft making a breif safety stop (in testing I would swtich to my primary air source at the safety from once the spare air was empty). In my 15+ years of scuba diving I have seen a number of unlikely events happen on dives, some to myself, some to other divers. These include a tank burst disk blowing half way into a dive at around 75 feeet, assorted regulator failures, some in non free flow condition, hose failures, etc.

Ike

Ike

 

[Sideband]

Dunno if it was you or me, but one of us sure knows how to kill a thread.

Joe

 

[scubarama]

I'm new to scuba board so forgive me if this is the bazillionth time for this one.
I'm a warm water no deco no wreck penetration diver I LIKE THE PRETTY FISH. there i said it. I dive with my wife all the time with our own equipment. She says we don't need it. I have to admit I've seen maybe one or two people with one.
Spare air bottle- yes or no if yes smaller one or bigger one.

 

[pt40fathoms]

Save the money and buy a really nice dive light instead.

That way you can see all the pretty fish at night as well.


A spare air has its place, however, scuba seems not to be one of them.

 

[Wijbrandus]

Warm water, no deco, no penetration - no need.

If you do anything that you can't rely on your buddies air or an easy CESA from 60' or so, sounds like you want a pony bottle.

"Spare Air" doesn't get good reviews on this board. A search will provide you a wealth of information far beyond my meager input.