Is a Pony Bottle too complicated for a beginner?

[grf88]

I have only skimmed through the 14 pages of responses but did not see any mention of cold water diving where free-flows can be quite common. Having two people breathe off of one first stage can result in the donors reg free-flowing as well especially when the receiving diver is a little panicked and breathing heavily. I have seen a number of double free-flows and all too often they result in a rapid ascent. By cold water I mean sub 40 degrees.

 

[skippy311]

As a beginner, in 1975 I was introduced to employing compact twin tanks. They are light, streamlined, you mount two independent regs providing you great safety, and the management is not complex. Much easier than using a pony tank hanging around.
Compact twin sets were the standard entry-level scuba system here in Italy until around 1981, when the first 15 liters tanks appeared. For diving in the Mediterranean sea, a standard AL80 or LP72 is definitely too small..

Hello! Can you still dive double tank?

 

[Lorenzoid]

I have only skimmed through the 14 pages of responses but did not see any mention of cold water diving where free-flows can be quite common. Having two people breathe off of one first stage can result in the donors reg free-flowing as well especially when the receiving diver is a little panicked and breathing heavily. I have seen a number of double free-flows and all too often they result in a rapid ascent. By cold water I mean sub 40 degrees.

Yeah, I know it's 14 pages, but it was mentioned somewhere. I have been on the side of arguing a beginner should avoid a pony bottle and stick to their training ... so long as the beginner is diving in conditions similar to those in which they were trained. Isn't that what we were all taught in OW class that our training qualified us to do?--and then, if our goal becomes to dive in more complex conditions, work our way toward that goal. If a diver progresses to diving in near-freezing water, then by all means the diver should consider adopting whatever equipment is considered appropriate for that. I don't think it's very common for OW classes to be given in sub-40F water, but if a beginner were to receive their OW training in such conditions, I would hope it included the use of a pony bottle or some other way to deal with the free-flow air-sharing problem you noted.

 

[scubaozy]

"Normally" is the magic word here. Occasionally equipment fail too and I don't know about you, but I want to be prepared for that case too.

I should replace “normally” with “actually”. I do not believe in magic or hokus pokus. There is something called fail safe design. Regulators are designed with that principle.

 

[Angelo Farina]

Hello! Can you still dive double tank?

Yes, of course. Why not?
I and my wife still own our two Technisub ARALU twin sets, made of a twin 9+9 liters alu tanks at 200 bar, providing roughly 3600 liters of air.

However, we also own a 15-liters steel single tank, at 232 bars, providing almost the same amount of air. It weights just 15.4 kg instead of 23 kg, and it also requires 4 kg less of weights. As it is equipped with a double valve, we can use the same two separate regs we use on the twin tank.
I did never consider a single first stage with an octopus "safe enough" for me...
And I did never use any tank providing less than 3000 liters of air. Again, smaller tanks are not "safe enough" for me.

 

[Lorenzoid]

I should replace “normally” with “actually”. I do not believe in magic or hokus pokus. There is something called fail safe design. Regulators are designed with that principle.

I agree with your thinking. That said, it has been countered that while the most common of the rare failures would be for the reg to free-flow (i.e., a fail-safe mode), there are some apparently even rarer failure modes in which a reg could stop delivering gas. How rare, nobody in this thread appears to be able to quantify. I think something like the main spring would have to fail. Seems exceedingly unlikely to me.

 

[SlugLife]

I haven't yet seen anyone say you absolutely need a pony when buddy-diving, or that these scenarios are likely to occur. The point of carrying a pony (responsibly) is not that these out-of-air or equipment failures are likely, but rather being prepared for the unlikely event something did happen.

Some people also solo-dive, and that fact that air-share even exists and does happen is enough for a solo-diver to want redundant air.

 

[wetb4igetinthewater]

By cold water I mean sub 40 degrees.

Woot! I'm a warm water diver now here in the Puget Sound.

Not giving up my drysuit however!

 

[grf88]

Woot! I'm a warm water diver now here in the Puget Sound.

Not giving up my drysuit however!

That would actually be cool water diver.

 

[Lorenzoid]

I haven't yet seen anyone say you absolutely need a pony when buddy-diving, or that these scenarios are likely to occur. The point of carrying a pony (responsibly) is not that these out-of-air or equipment failures are likely, but rather being prepared for the unlikely event something did happen.

There are also other "unlikely events" that could happen to a diver, or for that matter, to a person doing some other activity. Generally, we equip ourselves to handle only those adverse events for which the combination of the likelihood of occurrence and the severity of the outcome outweighs the negatives of carrying and being ready to use yet one more piece of gear. It's not practical for even seasoned divers, even technical divers, to equip themselves for EVERY unlikely event. We equip for the common ones--sure. We equip for the severe ones--sure. For any given adverse scenario, we try to weigh the likelihood and severity together and decide whether taking yet another piece of gear makes sense.

Some people also solo-dive, and that fact that air-share even exists and does happen is enough for a solo-diver to want redundant air.

Again, this is the New Divers forum, not the Solo forum. The OP asked if a pony bottle is too complicated for a "beginner," and there have been some great responses both for and against.