Pony and spare air pointers....

[Srrh]

Hello fellow bublemakers...

This year, I've started consistently diving (relatively) deep...
130 Feet and lower ....

Soooooo, it downed on me that, out of safety for my buddy and I, I should probably get myself a pony...

Imagine two people sucking on a single tank at 130 feet or more in firgid water: it's an accident waiting to happen...not only will the single cylinder empty quikly, but 1st stage (although environmentally protected) will freze: I dive in sub 40 water (Canada)...

So, I first thought about the cute spare air thingy: but to be honest, at that depth, it will give me about 10 breath...

So I've decided to go for a 20 or 30 cub. feet pony instead...

1)Where to mount it ? I've seen one of those gizmos that allow you to fix it on the side of your main tank. It look way cool...but wouldn't you loose all wiehgt balance ? should one compensate with less lead on that side ? Is it any good ?

2)I've received conflicting info on this one...does one open the pony as he enters the water, or only when need be ? if it's affixed on the main tank, one must open it before I suppose...

3)What is the difference (if any) between a pony bottle and a "stage" botlle...?


Thank-you

 

[LGH]

If you're serious about diving at that depth in cold waters I suggest you go for a double tank solution instead. Even a smaller double tank solution one will be much easier to deal with than a single plus a pony bottle. Plus a pony bottle will not last long at 130 feet, especially as the out of gas diver is bound to be consuming a lot of air (fear or nervousness because of loss of air source at depth). With a double tank solution using separate first stages you can take your time and try to work out a solution for failed equipment instead of starting ascent immidiately (as you would do with a pony bottle).

 

[AndrewA]

I agree with LGH. Diving deep to 40m (130 ft) in cold water is serious diving. Indeed I would count this as "Technical Diving" , the NDL at 40 m on DCIEM tables is 8 minutes so you are really talking about deco diving. I would suggest that it would be good to take one of the entry level tech diving courses and let your instructor guide you in terms of kit configuration.

 

[brockbr]

Hello fellow bublemakers...

This year, I've started consistently diving (relatively) deep...
130 Feet and lower ....

Soooooo, it downed on me that, out of safety for my buddy and I, I should probably get myself a pony...

Imagine two people sucking on a single tank at 130 feet or more in firgid water: it's an accident waiting to happen...not only will the single cylinder empty quikly, but 1st stage (although environmentally protected) will freze: I dive in sub 40 water (Canada)...

So, I first thought about the cute spare air thingy: but to be honest, at that depth, it will give me about 10 breath...

So I've decided to go for a 20 or 30 cub. feet pony instead...

1)Where to mount it ? I've seen one of those gizmos that allow you to fix it on the side of your main tank. It look way cool...but wouldn't you loose all wiehgt balance ? should one compensate with less lead on that side ? Is it any good ?

2)I've received conflicting info on this one...does one open the pony as he enters the water, or only when need be ? if it's affixed on the main tank, one must open it before I suppose...

3)What is the difference (if any) between a pony bottle and a "stage" botlle...?


Thank-you

Srrh,
This is meant as constructive feedback...

1) What is your SAC or RMV? Assuming a close-to-normal SAC of .6, a depth of 130ft is 5ATA. This means you're using 3 cu ft per minute on a "happy" dive. When things go bad, your SAC is going to at least double. That means YOU alone will be using 6 cu ft per minute.

2) Taking #1 into account, if your buddy messes up and runs out of gas, that means you'll be using 12 cu ft per minute from a single. Boy does THAT sound like a bad idea!

3) A 30 cu ft pony will last you how long in this situation?

4) On Air, your NDL for 130 is 10 minutes. At 140, your NDL is 8 minutes. What's the point?

5) You never mentioned an H-valve. You are setting yourself up for a bad day by not having redundant 1st stages on your single, regardless of what else you carry. For me personally, I won't go deeper than 100' on a single cylinder with only a single 1st stage.

For dives like you described, take other's advice and 1) Buy a set of doubles, 2) Get proper training. Proper in this case would be AN/Deco since you're going to blow past the NDL quickly at those depths.


b.

 

[Randy43068]

Hello fellow bublemakers...

This year, I've started consistently diving (relatively) deep...
130 Feet and lower ....

Soooooo, it downed on me that, out of safety for my buddy and I, I should probably get myself a pony...

Imagine two people sucking on a single tank at 130 feet or more in firgid water: it's an accident waiting to happen...not only will the single cylinder empty quikly, but 1st stage (although environmentally protected) will freze: I dive in sub 40 water (Canada)...

So, I first thought about the cute spare air thingy: but to be honest, at that depth, it will give me about 10 breath...

So I've decided to go for a 20 or 30 cub. feet pony instead...

1)Where to mount it ? I've seen one of those gizmos that allow you to fix it on the side of your main tank. It look way cool...but wouldn't you loose all wiehgt balance ? should one compensate with less lead on that side ? Is it any good ?

2)I've received conflicting info on this one...does one open the pony as he enters the water, or only when need be ? if it's affixed on the main tank, one must open it before I suppose...

3)What is the difference (if any) between a pony bottle and a "stage" botlle...?


Thank-you

LGH is correct. If this is the diving you're doing, get the correct gear and more training.

 

[Diver0001]

1)Where to mount it ? I've seen one of those gizmos that allow you to fix it on the side of your main tank. It look way cool...but wouldn't you loose all wiehgt balance ? should one compensate with less lead on that side ? Is it any good ?

Personally, I would sling it like a stage bottle. If the cylinder is made out of aluminium it won't put you off blance. Like any change you make it will require a (short) period of adjustment.

2)I've received conflicting info on this one...does one open the pony as he enters the water, or only when need be ? if it's affixed on the main tank, one must open it before I suppose...

Stage bottles are "charged" and then turned off until you need them but they are not intended to be part of your emergency contingency on the whole. The basic thinking about turning it off until you need it is that you know for sure it can't accidentally empty itself without you noticing. The down side to that, of course, is that when you need it you need to turn it on first.... My personal choice would be to leave it off until you need it based on the thinking that if you *need* it for your safety, then you *need* guarantees that it will be full when things go wrong....

3)What is the difference (if any) between a pony bottle and a "stage" botlle...?

nothing. A stage bottle is sometimes bigger than a pony but in terms of form or function there is no difference. Technical divers call them "stage" bottles because of their intended application, not because of the form or function.

R..

 

[AndyNZ]

I will put my oar in against the argument for twin tanks - potentially, they are an added complexity that you may not need.

With manifolded twins, unless you can identify and resolve problems (that may be happening behind your head) quickly then essentially you just have a big tank. For deco diving, yes... the redundancy it gives, especially when combined with a good team who will help resolve your issues, is unquestionably the best option.

For non-deco, the "large pony" as a bailout to give you enough gas to ascend is a simple and clean solution. I would have thought, though, that both you and your buddy would want to have a similar pony each.

Essentially, the pony is your contingency plan. You said this in your original post:

Imagine two people sucking on a single tank at 130 feet or more in firgid water: it's an accident waiting to happen...not only will the single cylinder empty quikly, but 1st stage (although environmentally protected) will freze: I dive in sub 40 water (Canada)...

Two people sucking on a single AL80 at 40m is not a problem at all - provided you have done your gas calcs correctly. You should always have a sufficient gas reserve for two people to ascend to the surface - if you don't know how to work this out, try searching for "rock bottom" or "minimum gas reserve" on the forums. You'll find plenty of threads that are relevant. Bob (NWGratefulDiver) has a very good article on his website.

As for the cold... well, will a regulator freeze? Maybe, maybe not - I've seen test results for some regs that have had dozens of people breathing off them in near freezing water. The first stage has ended up with a lump of ice around it, but it's still providing air. Yes, it is a risk... but not a certainty.

So the pony is your contingency. What I mean by this, is that the "risk" you are dealing with is one diver being out of air at depth. This is only acceptable if it occurs as a result of catastrophic equipment failure! Your mitigation of the risk is planning your dive so you have a sufficient gas reserve at all times for two people to share air to the surface.

Sometimes, ***** happens. So even though you have mitigated the risk it still fouls up. That's where the pony comes in - you've planned for the gas, but when you switch to your buddies octi the mouthpiece falls off, whatever... you then just switch to the pony and make a safe ascent with your buddy.

If you both have pony bottles, you have an additional reserve that you can share (only if you carry it as a slung tank) should another ***** happens event occur.

Depending on your breathing rate, and what you consider to be a "safe ascent", a 30 cu ft tank may be plenty big enough. But if you search for "rock bottom" you'll find the examples and can do the math, and work out what size tank is right for you.

 

[LiteHedded]

Hello fellow bublemakers...

This year, I've started consistently diving (relatively) deep...
130 Feet and lower ....

Soooooo, it downed on me that, out of safety for my buddy and I, I should probably get myself a pony...

Imagine two people sucking on a single tank at 130 feet or more in firgid water: it's an accident waiting to happen...not only will the single cylinder empty quikly, but 1st stage (although environmentally protected) will freze: I dive in sub 40 water (Canada)...

So, I first thought about the cute spare air thingy: but to be honest, at that depth, it will give me about 10 breath...

So I've decided to go for a 20 or 30 cub. feet pony instead...

1)Where to mount it ? I've seen one of those gizmos that allow you to fix it on the side of your main tank. It look way cool...but wouldn't you loose all wiehgt balance ? should one compensate with less lead on that side ? Is it any good ?

2)I've received conflicting info on this one...does one open the pony as he enters the water, or only when need be ? if it's affixed on the main tank, one must open it before I suppose...

3)What is the difference (if any) between a pony bottle and a "stage" botlle...?


Thank-you

doubles, helium, a competent buddy and TRAINING would be my advice.

 

[muddiver]

I'm with AndyNZ, doubbles are for cave divers, tech divers (DIR) and ventage divers that plan every thing, and do emergency drills every 4' during their dive.

A 30 cu is plenty for one (1) diver to leave bottom from 130' and make a safe ascent directly to the surface. I have done so using clse to 4.6 cu ft / min, which is the gas use rate of a diving helmet which far excedes any panicing scuba diver.

It might not be enough for two divers. Consider a 40 cu ft cylinder and sling it from your harness in front of you if you are planning for two divers. You should never have to feed two divers off on pony, both divers should have their own. It is also highly unlikely that both you and your buddy would be OOA at the same time so he should be ascending on his primary cylinder while you are on your pony.

As AndyNZ also inferred, the pony is your emergency egress to the surface, so do not include it in your dive plan. Plan your dive with the cylinder you are using as your primary.

When I use a 13 cu ft cylinder as my pony (shallow dives, clear, calm water) I strap it to the right side of my main cylinder with either an Akona pony pouch or I am going to try the new Zeagle pony straps. I mount it up sdie down so I can reach the valve and the valve is open to keep water out of the first stage. The pony is ballasted by moving 5 lbs of lead to my left side. If I am carrying any thing larger, like a 30 or 40 cu ft, I will sling it from the front of my harness. Also remember to subtract the amount of lead weight equivilant to the buoyancy of the pony for your dive.

On a side note, I hope you are diving an environmentally sealed, or cold water designed regulator.

 

[LiteHedded]

lower than 130' IS technical diving IMO
what's the NDL below 130 on the padi RDP anyway?