Is there a valid reason for a pony bottle

[doctormike]

I agree with you as to terrible options. But the fact remains, if the alternative is drowning, all other options are worth considering.

Sorry, no. CESA is a terrible option. Yes it is better than drowning, but that is sort of irrelevant. We are talking about a dive plan, which means decisions that are made long before an accident happens.

To PLAN to do a CESA in case of catastrophic gas loss when there is a better alternative, unnecessarily puts yourself at risk of DCS and AGE. So yes, it can save your life if you have such a failure. But it's better not to have that as part of your backup plan.

Finally, I really don't understand why the issue of gas planning keeps coming up with respect to the need for a pony bottle. I agree that a pony bottle should never be used like a J valve in the pre-SPG era - that is, as a substitute for gas monitoring.

A pony bottle IMHO is for sudden gas loss (i.e. LP hose failure, first stage failure, or unstoppable free flow). These are not extremely rare, one happened to me. The only other scenario where I can envision needing an alternative gas supply is if your run time is extended by unplanned events like entrapment or entanglement.

If you want to bet your life that your buddy skills are such that your buddy is as reliable as an alternative gas supply, that's fine, but I prefer to carry my own backup.

 

[KenGordon]

The pony side seem to be claiming that you need redundancy and so a pony is useful. I agree that you need redundancy (in some circumstances) but I claim that a pony is not very good as redundancy. It also brings risk of its own.

There are depths where a buddy is enough, and a direct ascent as a last ditch plan (but that is two failures, why were you still down without a buddy?). Then there are depths when a 3l pony is not enough, so there are twinsets.

How big is the range between the two?

So, pony users, at what depth do you stop using a pony and move to a twinset (or two sidemounted etc).

 

[Fastmarc]

I too cannot understand why the point of gas management keeps coming up.

 

[scubadada]

The pony side seem to be claiming that you need redundancy and so a pony is useful. I agree that you need redundancy (in some circumstances) but I claim that a pony is not very good as redundancy. It also brings risk of its own.

There are depths where a buddy is enough, and a direct ascent as a last ditch plan (but that is two failures, why were you still down without a buddy?). Then there are depths when a 3l pony is not enough, so there are twinsets.

How big is the range between the two?

So, pony users, at what depth do you stop using a pony and move to a twinset (or two sidemounted etc).

You choose a pony based on your gas needs from the deepest depths you will be diving. This is not rocket science, the calculation is a piece of cake.

 

[grf88]

If you come dive the Great Lakes or Newfoundland in early spring you will quickly understand why a pony or other redundant air source is a great idea. There are other locations of course but those are where I have seen the most free flows.

 

[saxman242]

There are depths where a buddy is enough.

Let's ask a more fundamental question: Under what circumstances is relying on a buddy to breath off of a better option than just grabbing the regulator on you that connects to a redundant supply?

In an emergency situation, would you rather go for the working regulator 6" away or the working regulator 6' away that now requires you to be tethered to someone else?

 

[MichaelMc]

Its not a safety device.

Consider the conditions that would require the use of a pony bottle. You've a) had a for serious equipment failure, b) lost your buddy and c) are unable to perform a CESA. All three of those things have to happen at the SAME TIME.

Equipment failures are rare, but do happen. Losing your buddy isn't acceptable. Search for a minute then up you go. If you can't do a CESA, you're not rec diving and need proper redundancy.

So what's the pony bottle for, exactly? So you can get away with not sticking with your buddy? So you can neglect your equipment? So you can bump up against the "limits"?

Which one of those things is acceptable? In my view...none of them. The "safety device" is just a pass to allow you to do unsafe and unacceptable things. No thx.

I do not get the railing of tech divers, who live redundancy, on rec ponies. Tech you have a buddy both with redundant air. Is double redundancy only allowed if your risk is high enough?

Is diving your full rig (rebreather or twins) so you stay in practice only allowed for tech divers. And not rec divers, that face varied risk levels?

Yes, a 3L pony is not great at the rec limit of 130’, but AL40 pony is pretty good, and might be greater than the reserve in a sidemount set.

Sure some dive it as a crutch or cluelessly, but some dive doubles as one big tank.

 

[rjack321]

I too cannot understand why the point of gas management keeps coming up.

Because pony bottle users almost always don't have one or just wing it with "back on the boat with 500psi" If you ask them how many CF it actually takes to ascend from their 120ft air dive they don't know but gumdangit they got their 13cf pony!

Most of us who have been on SB for many years have seen this exact thread over and over lol. At this point it's just a great means for me to figure out who I never want to invite onto my boat or cave dive with (and I have been diving with quite a few SB peeps over the years, nadwidny, pfcAJ, slacker, and lv2dive are four I know well).

 

[BRT]

Auto tires are pressurized 24x7x365=61320 hours each year. Scuba hoses are pressurized maybe 100 hours a year. Do you think that might be relevant?

Did you ever look at the inside of a tire that had been pressurized for years? It still looks like new. It is the outside that degrades, especially when it is usually parked with that side to the sun. I sell a handful of tires every year, 4 or 5 semi-loads. I have never seen an installed tire degraded on the inside unless it was run flat.

 

[MaxBottomtime]

A pony bottle IMHO is for sudden gas loss (i.e. LP hose failure, first stage failure, or unstoppable free flow).

These are not sudden gas losses, they are sudden leaks. Even using a small aluminum 50 as in the video I posted, you would have enough time to make an ascent and still breathe on the way up. For my dives, by the time I am at 50 cu feet of gas left, I'm already at or near the anchor and could ascend at any time. That's only if the leak occurs near the end of the dive. Any time earlier, I would be able to make an even slower ascent.