Should I buy a pony bottle?

[redacted]

A first stage failure almost always produces more bubbles than you would ever want. I doubt very much if a first stage failure to deliver any gas is anything more than a rather unlikely problem. Have you ever considered the chance of being killed by a meteor strike?

 

[skankpile]

Lets look at a al19:

If at 100feet 4ata and your LP goes with a catastrophic boom, your swivel blows, or 2nd unscrews you gotta bail out and you have 2min with a RMV of .8 to blow through 1/3 of the 19cf and start ascending to 20ft 1.6ata where you take 3 minutes using ~4cf of gas on a safety stop.. assuming you are careful about your ascents and go though maybe another 4 cf of gas during the ascents.. that should leave you with maybe 5cf left @600-700 psi. But.. one simple free flow on that 19 at depth...or blowing an SMB and the whole picture changes.

So if you really got to go with a pony and you are staying at recreational depths have at least a 19cf.

 

[redacted]

Lets look at a al19:

If at 100feet 4ata and your LP goes with a catastrophic boom, your swivel blows, or 2nd unscrews you gotta bail out and you have 2min with a RMV of .8 to blow through 1/3 of the 19cf and start ascending to 20ft 1.6ata where you take 3 minutes using ~4cf of gas on a safety stop.. assuming you are careful about your ascents and go though maybe another 4 cf of gas during the ascents.. that should leave you with maybe 5cf left @600-700 psi. But.. one simple free flow on that 19 at depth...or blowing an SMB and the whole picture changes.

So if you really got to go with a pony and you are staying at recreational depths have at least a 19cf.

Yes, a 19 should give you plenty of gas. My SAC is about .45. I have done 85 ft with more than 3 minute RS and slow ascent and boarding with gas to spare on my 13. A 13 travels easier than a 19. I also have a 19 for when air travel is not required - just in case I run into something interesting. A 30 or 40 just makes an OOA on your main tank a minor inconvenience.

 

[Hatul]

I don't believe we have shown that. We have pretty much agreed that a spare are is not usually going to allow an OOA diver to conduct a normal ascent on that redundant source of gas. If you have to perform a CESA, a spare air can provide a very helpful cushion in performing that task. And it packs for air travel quite easily. A 13 cf pony pushes your luggage weight limits. A 19 may push it real hard. A larger pony probably puts you into9 excess baggage charges. Fills need not be a problem with 2 regulators and a $5 adapter. May destination ops with a compressor will fill it with no concern about VIS. anybody ever seen a VIS sticker on a Cozumel tank?

If you do take a pony take two check-in bags, each is allowed 50lb, so there's no surcharge. Just get a luggage scale so you can distribute the weight properly.

 

[haumana ronin]

If you are mostly worried about first stage blowouts, H valves and Y vavles might be what you are looking for. If you do this, make sure you practice a lot before really counting on it.


:zen:

 

[TSandM]

Matt, diving with an attentive buddy should take care of your problems. But you are right; many people post stories of buddies who didn't perform as they hoped. And there is no guarantee that your "instabuddy" will have practiced ANY skills since OW -- we just taught a rescue class to two guys who had been dive buddies for several years, but who admitted they hadn't done a practice air-share since their original class. And they didn't do all that well when asked it do it from their rusty state!

You can minimize the problem of buddy separation by a careful pre-dive discussion, where you emphasize that staying together is one of your top priorities. But you will still need someone with the SKILLS to stay together, which in the kind of water where you have been diving, is not all that difficult. But in lower viz, it can be more of a thing.

Having your own redundancy is not a bad thing. (Cue the hissing as a huge SB audience that knows I'm a DIR diver inhales through its teeth.) Double tanks are great, but not available for rental in a lot of resort-type locations, and you have to learn to dive them to make them an advantage; without training and practice, they're actually worse than single tanks in terms of failure points. A simple, slung pony bottle has a lot going for it -- it's easy to carry, it's where you can see it, and it can even be handed off to another diver if need be. The biggest issue with pony bottles is that people underestimate the volume they need. You have to figure that if you need the pony, you're likely to be breathing a lot faster than you normally would. Since an Al40 is pretty comfortable and easy to sling (assuming your BC has the needed attachment points) it's hard to make an argument for something much, much smaller. I have not been happy with the balance of anyone I've dived with who mounts the pony bottle with brackets to the primary tank. That's also a bad place to have it, because you can't reach the valve on it, and you can't see the regulator attachment or first stage to troubleshoot problems. Watch Dumpster Diver's recent video of his son having to deal with the problem, when his pony bottle developed a massive leak.

It is GOOD that you are thinking of the what-ifs. It is good that you are considering various approaches. The approach I use to the problem you posited, of catastrophic gas failure, is to dive with attentive, trained buddies who practice skills regularly. On the occasions when I don't do that, I dive doubles, and I know how to use them. (I often try to find a third team member who's reliable, too.) In your case, obtaining an appropriately sized pony bottle and learning to be facile in its handling and use may be the best answer, given the pattern of diving that you are likely to do. Carrying a pony does NOT negate the other benefits of diving in a buddy team, though.

 

[PfcAJ]

A simple, slung pony bottle has a lot going for it

There was wailing and gnashing of teeth!

 

[mathauck0814]

A first stage failure almost always produces more bubbles than you would ever want. I doubt very much if a first stage failure to deliver any gas is anything more than a rather unlikely problem. Have you ever considered the chance of being killed by a meteor strike?

Any equipment failure at depth is not a death sentence - especially in recreational diving - this is the whole point of your training. Any diver has a redundant air supply. If solo, and your primary first stage goes, you'd shut the valve down and switch to your bail-out/secondary tank/pony bottle/etc. If with a partner, then your buddy has your backup gas on his back. Further if the divers who had died did so because of a first stage failure, it would be fairly simple to demonstrate that failure and document it as a contributing factor - I just haven't read any accounts where this were the case.

Dive safely. A pony is not a bad idea, especially if you have a tendency to end up far from your buddy. I only suggested the 80cf stage kit because it packs easily and they're readily available everywhere. Experiment with it - you can pick up a stage kit for ~$30 online or you can build one for even less. Not a bad way to go before you commit $200 to a tank. Whichever way you go, practice with it and know how to use it.

Odds are you'll never NEED it anyway.

 

[Pullmyfinger]

So you seem to be saying that staying a short distance from my buddy is a skill like any other skill. That's actually reassuring. I've just seen a lot of posts by experienced divers about diving with stranger buddies who basically deserted them. But hey, being close to my buddy will absolutely eliminate this danger that I was hoping to eliminate by the use of the pony bottle. So I'm happy to go with your solution. And I'm quite okay with having a little talk with a stranger buddy about expectations, and I think I can do it without alienating the person.

By the way, people talk about a failed first stage being extremely rare. But what about all these deaths by experienced divers where we don't know what went wrong? And of such deaths there are many, based on the little bit of reading I've done. What could cause an experienced diver to perish? Certainly, a failed first stage could do it. It's one thing to run out of air, switch to your alternate air source, etc. But it's another thing to find yourself sucking in sea water, start choking, and every time you choke you breathe in more sea water, etc. So it may be that a failed first stage is extremely rare. Or it may be that it's not so rare, but we don't hear about it because survival of such a malfunction is rare.

That's correct Matt. I subscribe to the viewpoint that staying close to my buddy is preferable.
This is more difficult if you are diving with a stranger, it may end up being that YOU are the one that is maintaining the close proximity.

Diving with regular dive buddies is the way to go.

-Mitch

 

[AaronRiot]

First thanks to the OP for posting this question. I too, as a new diver, and as a diver who will be doing a good amount of traveling on my own, have been considering the same thing.

To contribute to the thread here is my plan. Because I'm new I want to stick to mastering my core skills. I realize that there is a good chance that a lot of the people I come across over the years will be terrible buddies. For them, I'll simply stick to them like glue so IF they or I gets in trouble at least one of us made the effort to stick together, and we both come out alive. Conversely I'm sure that for every not-so-great insta-buddy I run into there will be an excellent one who values safety as #1 followed by preserving the fragile environments and so on and so forth.

My other thought about carrying the pony as a new diver is this: I WILL feel more comfortable, and the likelihood of me not stick as close as I should to a buddy I don't especially think highly of because they are wondering off or whatever increases. Not that I would on purpose. I would never. But it's my responsibility to give my buddy THEIR redundant air.

For example. Say my not so awesome buddy for the day is hanging onto a piece of reef and poking at a fish or something while the rest of the group starts moving away in the current. Wishing I was with the group (and that my buddy would hurry the &*%$@ up...or get bit...) I slowly drift 5 then 8 then 15 feet away from my buddy... I'm still pretty close right? Everything will be fine. I have no safety concerns to be thinking about because I have all the air I need if I run into a catastrophic failure. Wouldn't you know, that's the minute Murphy raises his head and bites my buddy in the ass. Now I have to get over to THEM because I have THEIR redundant air, and if they start choking etc. because I'm not close enough to save them I see that as my fault because that makes me just as poor of a buddy as them.

So I'm choosing not to carry a spare bottle, for now, and work on my core skills until I feel that they've been mastered. Then perhaps I'll move onto doubles. I would like that, and it's definitely a goal. For all the buddies in between that are a little less safe etc., lucky for them on that particular dive they have me as a buddy whose number one goal is that both of us surface. They may not be so lucky next time. On the plus side I'll get some practice sticking close to a less than cooperative subject...lol.

Just my thoughts, and remember I'm just a noob too..