Spare air/pony bottle---should I get one?

[barth]

Let me try a different approach since I think you are very sincere and it just a difference in perspective that separates our opinions.

The op is a diver that travels without a buddy. So at this point in his diving career a reliable buddy is not an option. So in your view that would mean solo diving, and that would mean a pony. But the op is not really trained for solo nor does he have the recommended experience. And beyond these obstacles some dive ops do not allow solo and others require a c- card, not an option at present. So that leaves self-reliant as the only viable option. And for many of us that means reduant gas.

I agree that if you agree to be buddies with someone, be a buddy and discuss expectations. It could be, as in my only experience with instabuddies, we both agree to mutual self reliance but still keep on eye out for the other. Other times its the even less ideal, but frequently use, option to using the guide as the DM and there are several recent threads addressing the problems with this approach.

So in the ideal black and white world dedicated buddy or solo rules but in the real world there is too much grey not to take steps to be self reliant.

I agree with you. , thanks for posting.

 

[mi000ke]

There are tons of treads regarding carrying a pony and I am guilty of starting a few of them. The more I read (here and elsewhere) and the more I dive, the conclusion I come to is this:

Learn about the various risks associated with diving. Learn about the extent to which each can be mitigated (or not) by equipment, technique/training, communication, etc. And then make your own decision. No one can tell you that you need to or can do X or don't need to or can't do Y. You can do whatever you want (subject to the laws and regulations of wherever you re diving) commensurate with the level of risk you are comfortable accepting. If you know what a SA can and can't do for you, then who am I to tell you you can't use one, even though I don't. My sister skydives, and I think that's insane. I won't do it with 3 chutes on my back. But diving......

I dive with a pony because every boat dive where I spend my winters is essentially a solo dive with a bunch of other divers nearby. We don't even make the pretense of buddying up. The DM checks on us every few minutes. I carry enough extra air to get to the surface in a leisurely fashion from my MOD or to swim to another diver or wait for the DM or someone to notice me. I am totally comfortable with the various risks. And when I die I hope it's while diving or mountain climbing (but not skydiving).

 

[barth]

I think this bears repeating, since some of the responses from very experienced divers seem to be missing the point.

A redundant gas supply is for one thing - catastrophic gas loss. This can be due to a free flowing regulator, a burst LP hose, etc... It is NOT for running OOG due to inattention. If that is the problem, you can't fix it with a piece of gear. So all the statements about watching your SPG are irrelevant in this discussion.

Therefore, AFIK, the two agencies that certify divers as self reliant (SDI and PADI) both require a redundant gas source. If you choose to solo dive without a redundant gas source, you may be fine in the event of catastrophic gas loss assuming that you have your wits about you to CESA immediately. I personally solo dive with a redundant gas source.

SDI does accept a H-valve as redundant airsource. Here are even self reliant divers who were using a single tank and H valve as redundant airsource (during the course while solo diving at 80 feet depth). One single failure (tank neck) can lose a divers gas.

23.8 - 2

https://www.tdisdi.com/wp-content/uploads/files/sandp/currentYear/SDI/part 3/pdf/individual/SDI Specialty Standards_23_Solo_Diver.pdf

 

[Diving Dubai]

My Input.

If you want a "pony" when you travel, Then take a travel sling and a spare reg set.

Learn to sling a tank, you might not be able to get hold of a small tank, and only option would be an AL80. I've slung one many times on vacation and never been charged.

I always have my pony filled with Air not Nitrox. The one time I've really needed a "pony" I was hauled down by a down current. At the time we were well within our rock bottoms of our back gas, that changed quickly.
In an emergency no-one has every wished they had less air.

It's easy for people to theorise from behind a keyboard, being in a real situation is a different thing. While a 13 or a 19CF can get you to the surface if your buddy goes astray, many other things can happen.

From experience I won't used a 40CF below 25m, for 30m+ for a site with big current etc, then it's an AL80 .

Here the thing, With a bigger cylinder you can use it as a range extender, as long as you respect the require gas volume for that depth. I personally breathe my pony on every dive, for the descent. I take 20 bar off the top. I do this so that I know it's working.

Of course everyone is different and I accept people have different views. Mine is born from personal experience of a normal dive going pear shaped

 

[Bob DBF]

Let's be generous and say that first stage can deliver down to a tank pressure of 150 psi, so

Please explain, any first stage I know will deliver down to 0 psi tank pressure relative to the regs surrounding pressure.

My take on A SpareAir is that it better to do a CSEA with one than without. If he takes it on every dive because it is easy and unobtrusive, that is much better than a larger cylinder that is left behind because it is a pita to deal with.



Bob

 

[drrich2]

Good luck with any sort of reasonable ascent from 100' with a spare air.

That's true. Compromises will be made in that scenario, as you've illustrated. Having a Spare Air 3 lends itself to less extreme compromises than having no redundant gas supply at all.

Of course, some catastrophic gas supply losses (e.g.: 2nd stage falls off the hose) may let you do the equivalent of breathing off a free-flowing reg., but let's assume that's not the case. Your redundant gas supply (or none) is all you've got. You may have exhaled right before the crap hit the fan.

As you pointed out, Spare Air 3 or no redundancy are not the only options on a 100 foot dive. One could...

1.) Dive with a reliable buddy. If that were a predictable, acceptable and consistent approach, this thread might not exist.

2.) Thumb the dive or stay much shallower, even if you've got the Spare Air 3. Some would, some wouldn't. Those who choose not to look to other options.

3.)

A 19 ft^3 pony is easy to travel with, weighs almost nothing under water and give you ample time to make a leisurely (30 ft/min) ascent from 100' with time for a safety stop

Since my experience is with a 30 cf pony in a stage kit at home, not a 19 cf, I'll have to imagine it. The 19 cf gives you almost 5x's the gas. Very nice advantage.

The Spare Air is more compact, skips the annoyance of trying to stow the hose between 1st & 2nd stages (there is none), comes with a holster that hugs my body closer than the stage kit (which dandles off 2 dead bolts) on my 30 cf pony, and all that's right out of the box. No DIY required. And I can fill that Spare Air without asking a shop to do it, and risking them insisting on doing a visual exam since the valve's been off it (which on a boat not set up for that, could be a problem).

Anybody suddenly out of gas at 100 feet would rather have the 19. No question. Some people will take a 3 cf Spare Air who'd otherwise 'just take their chances.' Regardless of how foolish that decision might seem, it is what it is. And having that little metal tube to whack Darwin or Murphy over the head before heading up might just make the difference. It'd be a rare thing, but somebody's gotta win the lottery...

Richard.

P.S.: Years back I asked about how hard it is to get the valve off, then back on properly tight, on a pony bottle since you've gotta have it off for air travel. Don't recall exactly what I was told, but I'm under the impression it's more involved that my Spare Air 3, which is surprisingly easy. Anybody care to comment?

 

[wetb4igetinthewater]

The probability of a catastrophic gas loss is very, very small. The probability of simultaneous catastrophic gas losses in the primary and secondary (pony, other sidemounted cylinder, other half of backmounted cylinders) is so small it is ridiculous to plan for. If one air source fails (even the backup) and you are diving solo, you abort the dive. Simple as that.

 

[AdivingBel]

The probability of a catastrophic gas loss is very, very small.

This^^^ and the probability of losing even an insta-buddy in a warm water, high viz environment is even smaller. I guess some folks have had horror story insta-buddies (hopefully actually had them not just heard of them because we've all heard fish stories ), so I can understand their reluctance to trust. I have not experienced a true horror story. My general experience (I can only truly go by that given a few hundred Caribbean/tropical like dive boat experiences) is actually pretty positive. I've had lots of excellent buddies; some so-so but safe buddies; a handful of newbies I've shepherded (which were highly rewarding); and a few that I've chosen not to splash with the first or second time. I have yet to feel "oh crap, I better have a pony" in the middle of a dive. Again as I posted earlier, if I'm doing a more challenging dive like a deep wreck, I would think twice about an insta-buddy; possibly sling a pony, or hire a guide for a buddy. Pre-dive preparation and consideration is your friend.

All that said, the OP asked for opinions and that's what he got along with justifications for those choices. Nobody was arguing for or against until posts like "I can't understand how..." or "let me put in to you another way (how I feel about it)..." There is a part of diving that is about mitigating risks and that's a personal choice. The reality is we're discussing reducing an already minute risk. Great for discussion even analysis, but the idea that diving in this environment with an insta-buddy is somehow outrageous or beyond acceptable is not born out by the reality of thousands and thousands of dives performed successfully. I don't mean to downplay very valid personally held beliefs by divers who via their posts I've come to respect. I for one hate it when divers buddy up with DMs/guides, but that's a different thread. Just some perspective. All IMHO, YMMV.

 

[wetb4igetinthewater]

Tand the probability of losing even an insta-buddy in a warm water, high viz environment is even smaller.

Disagree if your buddy has a camera in their hands. Vehemently disagree if both you and your buddy have cameras in both your hands. It is easy to drift apart, if neither party makes a conscientious and consistent effort to track the other. While I don't have this experience, but some insta buddies are racing somewhere (bottom of their tanks perhaps?) .

I'm a photographer ergo, I dive with redundancy. It is foolish not to.

 

[JohnN]

P.S.: Years back I asked about how hard it is to get the valve off, then back on properly tight, on a pony bottle since you've gotta have it off for air travel. Don't recall exactly what I was told, but I'm under the impression it's more involved that my Spare Air 3, which is surprisingly easy. Anybody care to comment?

Dead easy. Wax on, wax off grasshopper. . .

I believe it was RJP that first commented that a Spare Air is the only piece of diving equipment that allows you to go OOA twice on the same dive. If I was flying helo's over water, I'd absolutely have a Spare Air. Otherwise its a solution looking for a problem