Pony tank

[Edward3c]

I started with a Spare AIr maybe 10-15 years ago, then upgraded to a 19cf pony bottle and now I carry a 30 ct pony bottle.

You say that you always start your ascent with 1000 psi. When carrying a pony bottle I cut my main tank reserves roughly in half, so I'll start to ascend at around 600 psi and maybe have 300 at my safety stop and surface with 50-100 psi.

I've got the reserve in the pony tank so it allows me to draw my main tank gas lower, giving me extra gas on virtually every dive plus the safety of the redundancy of the second independent tank and regulator.

I have an integrated octo regulator as well, because on shallow reef dives I don't typically bother with the pony tank.

Using the extra cylinder as part of your gas planning means your using a stage cylinder not a pony. A pony is for when things go pear shaped.

 

[broncobowsher]

No, it's not only words. It is proper planning. Stage, Pony, Monkey butt, I don't care what you call it. It is about proper use and planning of said gas. You just threw your reserve away and are planning on returning with an empty tank. Returning with 50-100 PSI should be the plan in case the monkey butt gas doesn't work right, not your regular planning.

That is an accident waiting to happen.

 

[MaxBottomtime]

Unless there was a malfunction with your pony reg or the tank either drained during the dive or was not full to begin with. There is no logical reason to suck down your main tank just because you think you have a security blanket.

 

[grantctobin]

I started with a Spare AIr maybe 10-15 years ago, then upgraded to a 19cf pony bottle and now I carry a 30 ct pony bottle.

You say that you always start your ascent with 1000 psi. When carrying a pony bottle I cut my main tank reserves roughly in half, so I'll start to ascend at around 600 psi and maybe have 300 at my safety stop and surface with 50-100 psi.

I've got the reserve in the pony tank so it allows me to draw my main tank gas lower, giving me extra gas on virtually every dive plus the safety of the redundancy of the second independent tank and regulator.

I have an integrated octo regulator as well, because on shallow reef dives I don't typically bother with the pony tank.

This is extraordinarily poor advice. Please don’t do this.

 

[Ghost95]

It makes no difference weather you have a pony or not. Your gas calculations should be based only on your primary gas supply. If you're using your pony for accent, something has gone wrong.

Just get bigger tanks. (and then a pony)

Safe diving.

 

[Divin'Papaw]

I started with a Spare AIr maybe 10-15 years ago, then upgraded to a 19cf pony bottle and now I carry a 30 ct pony bottle.

You say that you always start your ascent with 1000 psi. When carrying a pony bottle I cut my main tank reserves roughly in half, so I'll start to ascend at around 600 psi and maybe have 300 at my safety stop and surface with 50-100 psi.

I've got the reserve in the pony tank so it allows me to draw my main tank gas lower, giving me extra gas on virtually every dive plus the safety of the redundancy of the second independent tank and regulator.

I have an integrated octo regulator as well, because on shallow reef dives I don't typically bother with the pony tank.

I’m also in the DON’T DO THIS EVER camp. Some of the worst advice I’ve seen WRT an alternate air source/pony bottle. It should NOT be part of or influence your gas plan for the dive. It is sized based upon your deepest planned depth & your RMV. It is then ignored in terms of your planned dive. It is for extreme gas loss emergencies only.

 

[Divin'Papaw]

Notice now the ones who say I am giving bad advice say it's because you "shouldn't use a pony in your gas calculations" as if that perfectly good bottle full of gas doesn't exist.

To them I say this: Gas is gas, whether it's split between an AL80 and a 30cf pony or a larger tank- I still surface with more gas than the average AL80 single tank diver.

It's perfectly safe- and I have the redundancy as stated.

If you think my advice is bad then give a good reason besides "you shouldn't do it"

Because that's not saying anything at all.

Because if you’re planning on it being there it’s not a redundant, emergency air source. It’s not your gas reserve it’s your redundant air source. Those are two very different things. If you don’t get that then take a solo course.

 

[scubapr1705]

Ok. So, if I understood the "problem" correctly, it is based on naming his second tank a "pony".
If he names his second tank as just his second tank, then there is no problem?

 

[Divin'Papaw]

Ok. So, if I understood the "problem" correctly, it is based on naming his second tank a "pony".
If he names his second tank as just his second tank, then there is no problem?

No, it’s not just about the name. He’s using it as a stage meaning he doesn’t have true redundancy in a proper alternate air source. It doesn’t provide the safety & conservatism required for a ‘pony bottle’ or alternate air source.

 

[Ghost95]

A pony tank is something that you don't plan to use. A second tank, or double, is planned for use.

But this is my opinion and how I learned.