Spare Air

[Narcd_dvr]

Its more about security than anyhing else.
Scenario: Reg fails at 120 fsw and buddy is around behind a large sponge for a second or behind a coral pilar. Panic sets in and wham, instant disaster.

I tell myself all the time, as do many of us, we could handle that scenario just fine and remain calm... Find our buddy.... and get the octo.

Thats precisely why I carry a pony. Once you get one, you have another choice to make and that is, how to mount the tank. You can either strap the pony to the main tank or side mount it. You can search the boards for opinions on this matter. I wont go there

Enrique

 

[scubatoys]

Yes... if you want something for bail out... I like them, and as far as cost effective, you're looking at a bit less than $200 for the spare air. Unless you have extra gear lying around, I don't know you can get a tank, 1st stage, 2nd stage and a pony gauge, plus you then still need some mounting brackets or straps. Can all that be had for sub 2 bills?? Probably not unless you already have some of the stuff...

In the end, when I travel to some locations, I just cannot have an extra 10 lbs in my bag. And if I'm at 100 feet and have some bizarre out of air emergency, I will easily make it to the surface with 3 cubic feet.

For me I've decided 3 cubic feet on my side is more valuable than 19 cubic feet in my closet.

I'm going to get one to Pete... our noble leader, so he can try one out on his next dive and then he can give us an semi-unbiased answer. I say semi-unbiased as he told me straight up that he has doubted the usefulness of the spare air, and has posted to that effect... So I'm going to get one in his hands so he can check it out and see what it does. Should be fun!

 

[The Kraken]

Now that's a good go, Larry and Pete !!!
Empirical data . . .

the K

 

[Wayward Son]

H2Odyssey makes a 6cf version. I don't have one, have never used one, am not recommending one. Just pointing out an option that has twice the air in case you want to take a look at it.

 

[LavaSurfer]

H2Odyssey makes a 6cf version. I don't have one, have never used one, am not recommending one. Just pointing out an option that has twice the air in case you want to take a look at it.

I am kinda liking the looks of the H2Odyssey Extra Air 13cf
Seems like the best of all worlds for small and functional.
3-5 feet for a safe ascent and the remaining 10 for a safety stop all in a compact unit.

[FONT=Verdana, Arial, Helvetica, sans-serif]Looks like Scubatoys sells them also.
[/FONT]

 

[Wayward Son]

Didn't know they made bigger ones.

I don't have a pony rig. I have thought a lot about it. Most of my diving is spear fishing, 75 to 100 FSW is common, sometimes a bit deeper. A redundant supply is appealing to me. It is a trade between acceptable capacity, manageability & extra weight. A 40cf is just bigger & heavier than i want to carry. Even a 30. I've concluded that for my most common dives, a 13cf is minimum & a 19 about the biggest I want to hassle with.

 

[Kaiser442]

Most people are just NOT going to carry a pony on vacation dives... and IMO 3cf of spare is a heck of a lot better than the (real) alternative - which is 0cf.

I don't have a spare air at the moment - but it is on my list (gotta buy my own regs first)

 

[markfm]

For me the 19 was based on my air consumption. Easy enough to figure out what works for a given person. Go to your max depth with an AL80, note your PSI, do a clean ascent, with whatever safety stops you would like, note your PSI back at the surface.

For me, safety stops consist of a minute at 35' plus 3 minutes at 15'.

Anyhow, when you know the delta PSI, convert it to cubic feet. An AL80, 3000 psi = 77.4 ft3 of gas. If I start ascent at 1250 psi, am at the surface at 600, I've burned 650 psi; (650/3000) * 77.4 = 16.8 ft3, so for me a 19cf is "right sized" without pushing things.

(The number comes out a bit under 19, definitely greater than 13, and I want a bit for adrenaline factor/analysis of what's wrong.)

Zero disagreement from me that a Spare Air or anything else may do the trick for a given diver, under their given conditions. Just trying to share my empirical method of determining what works for me, why I chose my particular configuration. Someone with a lower SAC could easily conclude that a 13CF works for them, same profile.

A 6CF tank is equivalent to 6/77.4 * 3000 = 232 psi on an AL80. If I could ascend cleanly from my maximum depth on that gas I'd be a happy camper For me, the really small bottles just wouldn't work unless I constrained myself to shallow dives, though I have no reason to doubt that some divers may pull it off.

As to whether people would be willing to take a pony on vacation, on mine there were two of us out of 19 -- call it 10%. I'm fortunate, pack light, so the pony was no issue, though the other pony user was at the opposite end of the spectrum, beaucoup luggage, but also chose to carry his rather than try to save a couple of pounds.

At the end of the day it's all about personal choices, comfort with risk. For myself, I made a conscious decision, early on, that I would dive with a pony backup, and have been consistent in carrying it. I surely can't fault others for their decisions one way or the other, just say what I do and why.

 

[Doc Intrepid]

Best of luck, Pete -- for those like me who suck air like a race horse, the SA is just too small. I'd get one deep breath, enough to contemplate the folly of my ways .

[JOKEMODE]

Dunno Mark, a Spare Air on that next vacation deep dive would probably give you just enough gas to remove your reg and recite the Lords Prayer on the way up, or maybe pull that reg out and scream "Dammit, I wish I'd sprung for a set of travel bands!"

http://www.aquaexplorers.com/double_bands.htm

[/JOKEMODE]

 

[markfm]

Neat idea, actually, the travel bands
Pursuit of technical diving is still a ways off for me, if I ever choose to go that route. I'm easily amused, truly happy to just check out the fish and wrecks within rec limits.