Pony 1st stage valve combo

[tbone1004]

@Schwaeble I have nothing against people carrying pony bottles, and @Marie13 I think a 30cf is really the minimum that you should take if you're diving deep, 80ft or more. At 100ft, you need 20cf/diver per rock bottom to make a safe ascent and deal with the situation. You also need a PSI buffer for the regs to behave which amounts to about 10% of the total volume. At 130ft, the 20cf becomes 34cf. Add in the 10% of the gas volume and that means an AL30 for up to 100ft, and AL40 for 100-130ft.

If I chose to dive with a pony, I would dive with nothing less than an AL30 for a 100ft dive, and nothing less than an AL40 for a 130ft dive. I do not believe in diving with less cubic feet than the depth I'm diving. I.e. an AL80 is good to 75ft, steel 100's are good to 100ft.
Reason for that is that at 100ft, you need to reserve 20cf/diver for ascent, and 10% so the regs breathe properly. Call it 46cf. That gives you 31.4cf to do the dive if at 100ft on an AL80 or about 13 minutes at the bottom for most people. That is not enough time for most people to be happy with their dive.

Based on buoyancy characteristics, the AL40 behaves better than any of the other bottles and while it is much larger than the rest, it is the least negative when full which means it disappears more easily when diving.

So, in my opinion, if you're going to carry a pony, make sure you do the math and it makes sense. For me that math is 5 minutes at depth at 1cfm. 5 minutes at 15ft at 1cfm. Total there is 20 or 25cf at depth plus 8cf for safety stop. I usually add 6cf for the ascent. For me, that means I need 40cf held in reserve somewhere for me to make a safe ascent, plus the same held in reserve for my buddy to make a safe ascent if I want to be conservative with it.

Is that too conservative or not conservative enough? For me personally, that is VERY conservative, but at the same time I have no idea what the state of a buddy will be so I'd rather have it and not need it, than need it and not have it. That is truly what I do for dive planning when I'm diving with students or divers I'm not familiar with. If I'm diving with buddies I know and trust? That number usually gets cut in half. We likely aren't taking a long safety stop if at all because we dive with a conservative algorithm. The 5 minutes at depth for situation resolution gets adjusted based on where we are. If on a long wreck, then it may well get longer since I only plan on going 25ft/min linear while in conflict mode and I want to get back to the anchor line before I begin my ascent. If i'm diving where I can truly make an immediate ascent, then it will get cut to 2 minutes. All depends.

For me that means I'm diving doubles or sidemount at 100ft not singles unless I'm with buddies that I know and trust completely. This is not really for redundancy, mainly for gas volume.
@victorzamora and I will be doing a bunch of dives this summer for some drysuit prototype testing in our local mud pit. We will be alternating between doubles with some prototype single hose regulators and my new Argonaut Kraken. I likely won't dive with a secondary on the Kraken, and I'll be diving single HP120's or LP121's. We'll be going to 120-130ft, and I have no problem with that... with him.
Only time I am going for redundancy is if I don't trust my buddy to be there for me if I need him and/or am not comfortable making a CESA. A first stage failure is distinctly unpleasant and I have experienced one in a cave so am a bit skittish personally


So, that was a long rant that probably didn't tell you anything.
So ask yourself these questions
Why are you carrying the pony? If you carry one, you are lacking confidence in one of three things. Reliability of your regulator, reliability of your ability to monitor your gas, or reliability of your buddy to act as your redundancy.
Which of combo of those three things is requiring you to carry the bottle in the first place?
Can you remedy any/all of those three issues so you aren't using the pony as "an equipment solution to a skills problem"- @cerich 's best line. Hint, the second two are examples of an equipment solution to a skills problem, the first is inappropriate equipment.

If you decide that you can't remedy those situations above for whatever reason, you have to ask the following.
Do you reserve the gas volume required in your tank and trust that in the event of a valve or first stage failure you use your buddies gas?
Do you carry one buddy bottle for the team for gas reserves *requires good buddy diving, not same ocean diving*?
If you have buddy concerns, do each of you carry your own pony bottle in order to have independent gas supplies?
Is the buddy bottle set up as a donate bottle in lieu of your octo in a secondary donate paradigm like @Marie13 ?
Do you use a primary donate regulator system with a normal secondary on a suicide strap and use the buddy bottle to pass to the OOA diver after everything has stabilized?
Do you use the pony bottle in lieu of a secondary and still use a primary donate paradigm *imo only useful if the bottle is mounted to your tank*?

Only after you answer all of those questions internally can you make the decision of whether the added cost and complexity is worthwhile. If it were me and I decided I'd need one while travelling, I'd carry a set of travel doubles bands and rig up a pair of AL80's and dive doubles. Much easier than a pony system and much better since you get a lot more gas reserve.

Realistically, I just reserve the appropriate amount of gas in my tank and deal with the risk of poor buddies.

 

[Schwob]

@tbone1004
And there I thought I am the guy with a lot of questions!
But I really appreciate!
But I got to read that a few times!

I can tell you I did the math before I got my AL40, nicely in a spreadsheet. And arrived at an AL40 as the least I would want solo to around 100' and beyond is a stretch.

My primary motivations are limited trust in a (some) buddy as well as solo diving.

I would like to just dive with my primary in my mouth (long hose or not) and my secondary on a suicide strap under my chin, whether that comes from a first stage on the pony or from the first stage of a larger tank that is part of the gas plan.

I tried that and like it. I am not doing it yet. I could do it when solo and then not when with a buddy bread to pull that Octo from the malfunctioning octoholder in the golden triangle. E.g. my son. Now, between my son and I, we may get that worked out on our trip to FL. But so far, when I dove with him (since using a pony) I had the pony with the valve colsed, hose powered and the primary jjust strapped to the tank as if it was a stage. And on my back tank I just had the regular primary and ovto setup that he uses. Once he is wanting to switch to using a suicide strap for the secondary we both will and will then practise primary donate. Until then, hodgepodge.

Now, assume my wife becomes OW certified early August and we dive together post cert. I don't know exactly yet what she will be taught in her class (need to read that book) in terms of primary donate or taking the Octo or..., but whatever it is, on our initial shallow dives I will be set up just like that.
And will have a pony slung for in case (just like a stage).... as something she does not need to worry about... If I bring a pony it can only be a 19 for weight reasons (whe certainly won't go south of 60' and maybe not south of 40'.
If I can source another tank there it will be a 40 or an 80.
So if I bring that 19 it cannot hurt...
Except, you are right, a transfil whip does not weigh nothing. But oddly enough, even so it could be a deadly whip (a first stage swung on a hose even more so) it can go in the cabin of the aircraft, the pony cannot....

For right now that's the extent of the wisdom applied. On the outside chance she uses a suicide strap in her OW class I'll bring mine and bungee cord... No need to worry her now... about more options or other ways.

And I am thinking I let her instructor weigh in a bit to on the initial advise part on how to rig up for diving with her.

After all that instructor is a good part of the reason she takes the class there (and decent vis and warm water)

So, those are our immediate diving pLans and that was the immidiate motivation to look at a travel pony. The sorting out of my diving style is on the back burner until after that family trip...

 

[USMC CPL.]

@Schwaeble I have nothing against people carrying pony bottles, and @Marie13 I think a 30cf is really the minimum that you should take if you're diving deep, 80ft or more. At 100ft, you need 20cf/diver per rock bottom to make a safe ascent and deal with the situation. You also need a PSI buffer for the regs to behave which amounts to about 10% of the total volume. At 130ft, the 20cf becomes 34cf. Add in the 10% of the gas volume and that means an AL30 for up to 100ft, and AL40 for 100-130ft.

If I chose to dive with a pony, I would dive with nothing less than an AL30 for a 100ft dive, and nothing less than an AL40 for a 130ft dive. I do not believe in diving with less cubic feet than the depth I'm diving. I.e. an AL80 is good to 75ft, steel 100's are good to 100ft.
Reason for that is that at 100ft, you need to reserve 20cf/diver for ascent, and 10% so the regs breathe properly. Call it 46cf. That gives you 31.4cf to do the dive if at 100ft on an AL80 or about 13 minutes at the bottom for most people. That is not enough time for most people to be happy with their dive.

Based on buoyancy characteristics, the AL40 behaves better than any of the other bottles and while it is much larger than the rest, it is the least negative when full which means it disappears more easily when diving.

So, in my opinion, if you're going to carry a pony, make sure you do the math and it makes sense. For me that math is 5 minutes at depth at 1cfm. 5 minutes at 15ft at 1cfm. Total there is 20 or 25cf at depth plus 8cf for safety stop. I usually add 6cf for the ascent. For me, that means I need 40cf held in reserve somewhere for me to make a safe ascent, plus the same held in reserve for my buddy to make a safe ascent if I want to be conservative with it.

Is that too conservative or not conservative enough? For me personally, that is VERY conservative, but at the same time I have no idea what the state of a buddy will be so I'd rather have it and not need it, than need it and not have it. That is truly what I do for dive planning when I'm diving with students or divers I'm not familiar with. If I'm diving with buddies I know and trust? That number usually gets cut in half. We likely aren't taking a long safety stop if at all because we dive with a conservative algorithm. The 5 minutes at depth for situation resolution gets adjusted based on where we are. If on a long wreck, then it may well get longer since I only plan on going 25ft/min linear while in conflict mode and I want to get back to the anchor line before I begin my ascent. If i'm diving where I can truly make an immediate ascent, then it will get cut to 2 minutes. All depends.

For me that means I'm diving doubles or sidemount at 100ft not singles unless I'm with buddies that I know and trust completely. This is not really for redundancy, mainly for gas volume.
@victorzamora and I will be doing a bunch of dives this summer for some drysuit prototype testing in our local mud pit. We will be alternating between doubles with some prototype single hose regulators and my new Argonaut Kraken. I likely won't dive with a secondary on the Kraken, and I'll be diving single HP120's or LP121's. We'll be going to 120-130ft, and I have no problem with that... with him.
Only time I am going for redundancy is if I don't trust my buddy to be there for me if I need him and/or am not comfortable making a CESA. A first stage failure is distinctly unpleasant and I have experienced one in a cave so am a bit skittish personally


So, that was a long rant that probably didn't tell you anything.
So ask yourself these questions
Why are you carrying the pony? If you carry one, you are lacking confidence in one of three things. Reliability of your regulator, reliability of your ability to monitor your gas, or reliability of your buddy to act as your redundancy.
Which of combo of those three things is requiring you to carry the bottle in the first place?
Can you remedy any/all of those three issues so you aren't using the pony as "an equipment solution to a skills problem"- @cerich 's best line. Hint, the second two are examples of an equipment solution to a skills problem, the first is inappropriate equipment.

If you decide that you can't remedy those situations above for whatever reason, you have to ask the following.
Do you reserve the gas volume required in your tank and trust that in the event of a valve or first stage failure you use your buddies gas?
Do you carry one buddy bottle for the team for gas reserves *requires good buddy diving, not same ocean diving*?
If you have buddy concerns, do each of you carry your own pony bottle in order to have independent gas supplies?
Is the buddy bottle set up as a donate bottle in lieu of your octo in a secondary donate paradigm like @Marie13 ?
Do you use a primary donate regulator system with a normal secondary on a suicide strap and use the buddy bottle to pass to the OOA diver after everything has stabilized?
Do you use the pony bottle in lieu of a secondary and still use a primary donate paradigm *imo only useful if the bottle is mounted to your tank*?

Only after you answer all of those questions internally can you make the decision of whether the added cost and complexity is worthwhile. If it were me and I decided I'd need one while travelling, I'd carry a set of travel doubles bands and rig up a pair of AL80's and dive doubles. Much easier than a pony system and much better since you get a lot more gas reserve.

Realistically, I just reserve the appropriate amount of gas in my tank and deal with the risk of poor buddies.

So when I start tec training would a 40 cf tank be ok for decompression/bailout???? I am going tec 40 and may 45.

 

[tbone1004]

@USMC CPL. al40's are the preferred deco bottles for most people. 30's work ok, especially in the salty stuff, but the 40's are a bit nicer. I have both and wish I could ditch my 30 for a 40.

@Schwaeble the primary donate paradigm is actually in the golden triangle when diving in proper trim, the secondary donate/take is not. The risk of having a pony charged but valve off is that if a diver grabs said pony regulator for whatever reason, they get about 1 breath and then nothing which could invoke a panic situation. May not, but it may. I would recommend moving to a primary donate sooner rather than later and not have to find out the hard way.
Regardless of how your family has been trained, they haven't actually practiced that skill enough in most classes to where there is a lot of muscle memory ingrained and you are going to be better off switching them to a superior regulator configuration immediately as opposed to letting the other styles sink in which will make the transition more difficult.

If the instructor has the option, have him train her on an Air2. That way she gets used to primary donate and the transition from an Air2 to a suicide strap is super simple and easy, switching secondary donate to primary donate is not.

So, at 40 or 60ft, you have slightly easier math to make an al19 work, but. You still have to answer the questions above to figure out why you need it for that trip and what it gives you vs. just renting an extra AL80, or relying on proper buddy techniques to mitigate the need for one in the first place. I can't answer those questions, on you can.

 

[Doby45]

I would like to just dive with my primary in my mouth (long hose or not) and my secondary on a suicide strap under my chin, whether that comes from a first stage on the pony or from the first stage of a larger tank that is part of the gas plan.

I would say you would need to keep two regs on your primary air source. I would hate to have a reg on my primary air and a reg on my "bailout pony" and nothing more. What happens if you have a secondary reg issue on your primary air, you swap to your pony and now you only have your pony air to work with. Keeping two secondaries on you primary air source allows you the opportunity to stay on your main air, resolve the issue or simply continue the dive and count on the pony if you have ANOTHER secondary issue.

 

[tbone1004]

I would say you would need to keep two regs on your primary air source. I would hate to have a reg on my primary air and a reg on my "bailout pony" and nothing more. What happens if you have a secondary reg issue on your primary air, you swap to your pony and now you only have your pony air to work with. Keeping two secondaries on you primary air source allows you the opportunity to stay on your main air, resolve the issue or simply continue the dive and count on the pony if you have ANOTHER secondary issue.

second stage problems are going to require feathering the valve in order to keep breathing off of it if it is freeflowing *they almost always fail open unless they get clogged*. The key to your problem is to size your pony appropriately. These 19cf ponies are WAY undersized for most people to make a proper ascent strategy. If you are that concerned, then you have to go to a truly redundant system *doubles or sidemount*

 

[Doby45]

second stage problems are going to require feathering the valve in order to keep breathing off of it if it is freeflowing *they almost always fail open unless they get clogged*. The key to your problem is to size your pony appropriately. These 19cf ponies are WAY undersized for most people to make a proper ascent strategy. If you are that concerned, then you have to go to a truly redundant system *doubles or sidemount*

I agree with you but saw it just this past weekend. Primary secondary reg has the exhaust flap flip a certain way and it gets held open. Reg is basically in a constant flood and you could easily swap over to your backup secondary and continue the dive on your primary air source. Pony never gets deployed. Easy fix above water and hell might even be an easy fix under water if you can find a little pokey thing to lay the exhaust flap back down. For me personally, I still want at the very least redundant secondaries on my primary air source, even with a pony.

 

[2airishuman]

What should one think about these pony valve 1st stage regulator combos

They provide a slight savings in weight and bulk during the dive at the expense of being more difficult to fill and maintain. In general, and with practice, a standard stage-rigged bottle works just as well.

Any other thoughts / wisdom / insight ?

tbone has read to you from the Gospel of the Large Pony all the way to the triumphant conclusion that Doubles Really Are Better So Don't Bother.

I like doubles and use them on many dives, particularly deep solo dives. They pose various logistics problems however which make them impractical in most situations I encounter.

I bring a pony on certain dives and it is sized to be sufficient for an immediate ascent for one diver. I have several sizes available but usually use an AL19.

There is a tendency on Scubaboard for people to recommend really large pony cylinders based on hypothetical scenarios and multiple layers of reserves. You decide for yourself if that is necessary.

 

[USMC CPL.]

@USMC CPL. al40's are the preferred deco bottles for most people. 30's work ok, especially in the salty stuff, but the 40's are a bit nicer. I have both and wish I could ditch my 30 for a 40.

@Schwaeble the primary donate paradigm is actually in the golden triangle when diving in proper trim, the secondary donate/take is not. The risk of having a pony charged but valve off is that if a diver grabs said pony regulator for whatever reason, they get about 1 breath and then nothing which could invoke a panic situation. May not, but it may. I would recommend moving to a primary donate sooner rather than later and not have to find out the hard way.
Regardless of how your family has been trained, they haven't actually practiced that skill enough in most classes to where there is a lot of muscle memory ingrained and you are going to be better off switching them to a superior regulator configuration immediately as opposed to letting the other styles sink in which will make the transition more difficult.

If the instructor has the option, have him train her on an Air2. That way she gets used to primary donate and the transition from an Air2 to a suicide strap is super simple and easy, switching secondary donate to primary donate is not.

So, at 40 or 60ft, you have slightly easier math to make an al19 work, but. You still have to answer the questions above to figure out why you need it for that trip and what it gives you vs. just renting an extra AL80, or relying on proper buddy techniques to mitigate the need for one in the first place. I can't answer those questions, on you can.

Thanks for the quick reply. 40 it is then.

 

[Couv]

Integrated first stage and valve subject aside; if you need to transfill a pony occasionally try this easy to carry fitting: Tank Equalizer for $2.50