Pony Bottle / Spare Air

[Jorgy]

As you can see the pony/no pony/spare air is very complex........and folks have very strong feelings about all of them........

Some thoughts........

Even a SpareAir still has a regulator that can malfunction or can be empty.........

Even a SpareAir could cause an entanglement.........

A pony should never be used for anything but an emergency.........and when you go to your pony your dive is over......you are going to the surface as safely as you can......

A front mounted pony can be given to a buddy.......also front mounting allows you to check if the reg is free flowing.......

Get a pressure gauge on the pony so you can check it is full........

A pony never replaces any part of of your standard dive gear, such as alternate secondary.......or any part of gas planning......or any part of diving with a good buddy.......

My hope is the my pony is an item I never ever have to deploy..........other than for training and to verify it works.......

M

 

[Chris12day]

Jorgy,

I agree....just like my DAN insurance.

Thanks

 

[scubaskipper]

If you're serious, the 30 at a min. the spare air is more of a crutch.

 

[Dr Wu]

No, being foolish causes foolish gas planning.


See above comment.


So can your main tank...check it.


See above comment.

I don't even get this one

So can your primary regulator but they both aren't likely to malfunction at the same time which is the whole point.

Anything can become entangled, if the bottle is too small get a larger one and too big isn't a problem.



Being human causes fatalities along with being underwater.

The OP asked for the cons of diving with a pony. I provided examples that have been the root cause of dive fatalities in the past. You may not like dealing with that reality but it does not change anything for the deceased divers.

You said you did not understand this one: They can be mistaken for the primary and run out.

Allow me to explain. When diving with multiple tanks one of the dangers is inadvertently placing the wrong second stage in your mouth and breathing from it. In the case of technical diving this potential problem is addressed in several ways. In the case of recreation divers what can happen is the diver places the pony in their mouth thinking it is the primary and has an OOA. They stress and think "Better switch to my pony" and find it is empty. This has happened in real life situations.

You stated: if the bottle is too small get a larger one

Every diver that ran OOA wished they had gotten a larger one. Unfortunately that is impossible to do while underwater.



Lastly, simply stating "Being human causes fatalities along with being underwater" shows an astonishing ignorance of how dive accidents occur and the way incidents are evaluated.

 

[Notso_Ken]

Please do. I cannot figure how 3cft would be insufficient to make an ascent that should take less than 20 seconds and at less than 1.5ATA.

Well, the figures I saw quoted earlier in this trail were for deeper, and also included a safety stop. So, let's look at that situation.

In a stressed situation, figger on an RMV of 1 cu ft/min. Take that to 33 feet, and your actual consumption (at 2 ata) is 2 cu ft/min. 3 cu ft is gone in 1 1/2 minutes. Ascent from 33 feet is 1 minute. Safety stop is 3 minutes. You're short a little air for a controlled ascent with safety stop from 33 ft.

I did these calculations for a friend that got a SA, she didn't believe me when I predicted she'd get 32 breathes out of it. We went to 33 feet, she switched over, and got 33 breathes on it. OK, I was off by 1 breathe.

If I run out of air, I want something that will give me a safety stop (ie, probably a 19 or so for my liking). If I want to skip the safety stop, I'll just do a CESA.


Ken

 

[scubadada]

The OP asked for the cons of diving with a pony. I provided examples that have been the root cause of dive fatalities in the past. You may not like dealing with that reality but it does not change anything for the deceased divers.

You said you did not understand this one: They can be mistaken for the primary and run out.

Allow me to explain. When diving with multiple tanks one of the dangers is inadvertently placing the wrong second stage in your mouth and breathing from it. In the case of technical diving this potential problem is addressed in several ways. In the case of recreation divers what can happen is the diver places the pony in their mouth thinking it is the primary and has an OOA. They stress and think "Better switch to my pony" and find it is empty. This has happened in real life situations.

You stated: if the bottle is too small get a larger one


Every diver that ran OOA wished they had gotten a larger one. Unfortunately that is impossible to do while underwater.



Lastly, simply stating "Being human causes fatalities along with being underwater" shows an astonishing ignorance of how dive accidents occur and the way incidents are evaluated.

Are you with it Dr Wu? Don't think so.

Good diving, Craig

 

[joe rock]

As you go deeper look at a pony bottle around the 6cf to 13cf size is good, you only need the bigger ones if you are pushing the no-deco limits or such like.

I have to disagree with this statement.
IMO, the size of the PONY is not dependent on "pushing the no deco limits" It's a function of the depth you dive and amount of air you feel you need to get you safely to the surface based on your SAC rate if an emergency happens.

For example a 13 cf pony would provide about 3.25 cf of air at 100 ft. My SAC rate is .60. That size pony would last me about 5 minutes at depth. Now my SAC is going to increase casue if I using my PONY something BAD just happened. Assuming the OOA situation has significantly increased my SAC rate to 1 or higher, I'd be cutting it REAL close on a direct ascent to the surface (3+ minutes for a safe ascent). Plus that would leave no air for a safety stop. (Yes, I know the air volume will increase as I ascend). This is just not enough safty for me. This would be the situation wheter I was at 100 feet for 1 minute or 20 minutes.

My recommendation is evalute the type of diving you do (depths you go to). Know your SAC rate and base your decisions on the amount of air you need to get safely to the surface with something left. As someone else said, you don't want to run out twice

JR

 

[SkimFisher]

 

[awakefie]

I have both and gear up based on the dive situation.

If you get a Spare Air make sure it’s serviced like any other regulator/tank. They are really simple regulators, but simple doesn't mean bullet proof.

If you get a pony then please put a gauge on it. I've seen them without more than I'd care too and finding out that your pony really wasn't full isn't a fun thing to 'find out' mid-dive.

Honestly, I never view the Spare Air as a 'Oh, darn I'm OOA or have a malfunction and its time to do a normal ascent and safety stop on my backup (Spare Air)'. With a pony you can do that depending on size and depth. In my opinion a Spare Air is a tool for a 'Oh, **** situation!'/CESA situation.

Though I suppose if your diving around at 20 feet and want to employ a Spare Air to finish a dive the normal way then go ahead. Of course a safety stop doesn't make a great deal of sense if you've been diving around at 20 feet.

Recommendation: If you come across a cheap Spare Air and plan on using it as a tool of last resort then grab it. If you’re looking for true redundancy then get yourself a mid-sized pony.

Whatever you do decide to do, go out and dive it and get used to before you find yourself in an emergency situation with it.

I guess, I just don't see a Spare Air and Pony as interchangeable pieces of gear.

 

[paddler3d]

Well, the figures I saw quoted earlier in this trail were for deeper, and also included a safety stop. So, let's look at that situation.

In a stressed situation, figger on an RMV of 1 cu ft/min. Take that to 33 feet, and your actual consumption (at 2 ata) is 2 cu ft/min. 3 cu ft is gone in 1 1/2 minutes. Ascent from 33 feet is 1 minute. Safety stop is 3 minutes. You're short a little air for a controlled ascent with safety stop from 33 ft.

I did these calculations for a friend that got a SA, she didn't believe me when I predicted she'd get 32 breathes out of it. We went to 33 feet, she switched over, and got 33 breathes on it. OK, I was off by 1 breathe.

Let me again say I'm not a fan of the SA.

With that said a recreational diver diving within OW limits (going for the 60ft limit here) these SA things will get them to the surface safely.

They are supposed to be diving within their NDL, which means that safety stops aren't required also this is still the realm where you can ascend at 60ft/min.

Even at a bad SAC rate 1.0ft³/min, you're going to have enough air to get to the surface.

For doing most reef dives were a lot of OW divers go, these things will work.

It has got to be safer than doing a CESA!