Skills For Carrying And Using A Pony

[ZzzKing]

If you are only going with one second stage on each cylinder, why wouldn't you just unclip and handoff the (slung) pony to your OOA buddy? And if you did that, would bungee-ing the pony second around your neck be a good idea? Maybe you are just talking about a mounted pony situation.

 

[2airishuman]

If you are only going with one second stage on each cylinder, why wouldn't you just unclip and handoff the (slung) pony to your OOA buddy?

Handing off a stage between divers is a skill that both must practice, as it is easy to drop the cylinder and lose it. Not something I would want to do under stress.

Then the question is one of where the most air is. There are two schools of thought. One school of thought is that OOA emergencies are most likely towards the end of the dive, and with proper gas planning and pony sizing there should be, immediately before ascent, be more than half as much air in the pony as in the back gas cylinder. According to this school of thought, having one diver (either one) switch to the pony at this point maximizes the overall available gas supply for dealing with the emergency.

The other school of thought is that divers have a responsibility to plan their back gas to include buddy rescue anyway so switching to a pony is neither necessary nor desirable.

And if you did that, would bungee-ing the pony second around your neck be a good idea? Maybe you are just talking about a mounted pony situation.

Depends on your configuration. I practice primary donate and have my alternate bungeed under my chin, and after thinking through the consequences in various scenarios, don't want to replace it with a pony reg.

 

[rongoodman]

If I was going to carry one, it would be slung, with its own second stage, minimum 30L. I don't see the point of bothering with anything less.

 

[Kairoos]

If I was going to carry one, it would be slung, with its own second stage, minimum 30L. I don't see the point of bothering with anything less.

Depends on the dive. I have a 30cf and a 13cf. The 13cf is more than adequate for recreational dives with no overhead, penetration, or light penetration of wrecks. At least it is with my SAC rate...

 

[dumpsterDiver]

Patoux01,

I'm not sure if there have been multiple accidents, or if I've heard the same account from different sources with different details, but there has been at least one death of a diver attributed to use of a pony tank. The two stories (or two versions of the same story, take your pick) I've heard are:

1) A diver lost his regulator during the course of a dive. Performing an arm sweep, he recovered what he thought was his primary regulator but what was in actual fact his pony regulator, which had not been properly secured. When the pony bottle was exhausted, an out of air emergency ensued.

2) A diver entered the water, thinking he was breathing his primary regulator but actually breathing his pony regulator. When the pony bottle was exhausted, he removed the regulator from his mouth. Thinking there was a problem with his primary air supply, he decided to switch to the pony, then correctly located and identified and tried to breath from the pony regulator.

These problems are made possible by four closely related equipment configuration choices:
a) The pony is mounted by attaching it to the primary cylinder, which can be done with any BC and minimum skill. However, it is difficult if not impossible to reach the cylinder valve during the dive.
b) Because of the difficulty reaching the valve, it is left open.
c) For simplicity, an SPG is not used on the pony.
d) Hoses for the pony and main gas supply attach to their respective 1st stages in the same area, contributing to the possibility of breathing the wrong reg.

Carrying the pony as though it were a slung stage is not possible with all BCs, and it's not as convenient, but it is much harder to mix up regs:
a) the pony reg is clipped off to the pony cylinder, making its purpose clear.
b) hoses are held in place by rubber bands or bungees and cannot be snagged during a lost reg sweep when endeavoring to recover the primary
c) because the valve is immediately accessible in this configuration, the cylinder may be carried valve off, which reduces any freeflow risk as well as reducing the risk of breathing the wrong reg. Even if carried valve on, the valve can be closed as a test if there is doubt as to which reg is being breathed.
d) An SPG can be used in this configuration if desired providing one more piece of confirming data as to what's going on.

I don't agree with your decision to sling the bottle and the size is probably larger than you need, but you seem to have researched the issues, assimilated a concept of what you need to accomplish your goal and will pursue it. Your decision is entirely defensible and I understand it. Notice how nobody addressed your question about what you. Need to do to add this piece of equipment?/

Many people will say it is superfluous and complicated but when you ask what you need to practice ....there is silence.??

 

[wetb4igetinthewater]

[QUOTE="NetDoc, post: 7641642, member: 879"I really can't imagine anything smaller than an 80 having an appreciable effect.[/QUOTE]

My 19 cu ft pony bottle will make me roll to the right when I'm perfectly still.

 

[wetb4igetinthewater]

If you are only going with one second stage on each cylinder, why wouldn't you just unclip and handoff the (slung) pony to your OOA buddy? And if you did that, would bungee-ing the pony second around your neck be a good idea? Maybe you are just talking about a mounted pony situation.

Because that air supply is just for me. I'll share air from my main tank, but my pony is my pony. No one else gets to ride.

 

[Edward3c]

Wear it where it's most comfortable for you.

I always get assistance fitting mine (side slung), but I dekit it myself.

The pony is for me, if I want it I need it. Therefore it's on.

Every few months I practice a main cylinder failure at 35m. So far I've got to the surface without running OOG and having to go back to my main reg. I also shoot a DSMB as part of the drill.

 

[Patoux01]

when you ask what you need to practice ....there is silence.??

There's hardly anything to practice... Swapping regs? Sharing air? Really? The only thing maybe is donning and doffing, but there's really nothing complicated to that. I don't consider turning a valve that is right in my face to be something complicated to do either.




Pony-reg on bungee and main on a long-ish hose has the following advantages:
-your pony-reg wont let the slightest bubble out without you noticing
-that pony-reg wont be the one you find using an arm swipe, or your body shape must be very interesting.
-that same reg will be there, not stuck to your tank (as would happen with a clipped off reg), or maybe gone (as could happen with stowed)
-your buddy gets a reg that is 100% guaranteed to work and is breathable.
-you CANNOT mistake them, really. Anyone who's tried a "hog" rig knows that.
-it's as close as can be to your original setup (bungee'd alternate, therefore you're not changing procedures)

Mind explaining this:
"I do not subscribe to this school of thought because I do not believe it fulfills the implied safety commitment that I believe I make to the other diver."? I really don't understand what safety issue it causes.

A 20cuft tank taking you out of balance? Heck, we dive single tanks sidemount with 80s and it doesn't affect at all. But whatever floats your goat... Are you guys using heavy steel tanks for this maybe? (are there any in those sizes?)


More than happy to get proven wrong, but imo you're overcomplicating stuff.

 

[CuzzA]

Here's my thoughts on the configurations and skills. I think a lot of it depends on the activity you're doing while diving and where you're dropping in from. One configuration may be better than the other depending on the dive. I don't believe there's a one size fits all, so to speak, set up.

If you're doing any kind of diving in which a bottle in front/side of you doesn't impede the activity then I would sling it. Rig it like a stage bottle with clamps, bolt snaps and wheel barrow inner tube to secure the hose and reg to the bottle, a button SPG will suffice. Pressurize the system and depressurize before you drop. It's my understanding this is the technique most technical divers use. An alternative, which I've seen and read a lot of rebreather guys use is to add an over pressure relief valve on the first stage and a shut off valve on the second stage. This way the system is on and a quick pull on the valve allows the flow of gas. Some argue it adds failure points and is unnecessary. Perhaps a lot of CCR guys like the ability to quickly get on their bailout gas in case of some sort of failure with their unit. I don't know the reasons.

Then there is the option of tank mounting. I personally see tank mounting as the best option when doing activities like spearfishing and perhaps photography. A slung tank, in my practice, impedes my ability to freely pull bands, tussle fish and creates an entanglement point when line shafting. Some of this could be from my inexperience, but that's what I've found. So the question then becomes do I mount the tank inverted or upright. Obviously inverted gives you the ability to have valve control and also allows you to rig it like a stage bottle with the hose and reg secure for deployment. There's two issues with that. You can't leave the system on because you would not notice a free flow and second, you run a high risk of damaging the valve and first and second stage, especially if you're on a pitching boat or clip it on the gunnel. You could cure the free flow issue by necklacing the second or depressurizing the system. Of course consideration has to be made that in an emergency you must be able to access the valve.

Looking at the option of mounting the tank upright reduces the risk of damaging the valve and reg, but of course you may lose the ability to control the valve. And you must run the second stage to either your necklace or clip it off. Again the advantage of running the reg to your necklace is that you would be aware of a free flow, of course if you don't have valve control there's little you could do to stop it. Although, depending on the size of your main back gas tank you may actually be able to reach it. I dive big Faber 112's and can reach the valve on my 19 as it is mounted low enough to grab hold of the valve.

A couple other suggestions about configuration would be identification and inadvertent deployment that needs to be secured. You can buy colored mouth pieces, hoses and face plates. Any of those things will help to quickly identify which reg is which. I would also consider adding bolt snaps to all of your second stages especially if the pony reg is not necklaced. The reason being is if you have to go to your pony you would want to be able to clip off your primary, especially if it's a long hose. You don't want 5 or 7 feet of hose just floating around you. Also if you inadvertently deployed the pony reg or it became caught on something and was deployed you would want the ability to just clip it off especially if the situation does not allow you to resecure it with tank rubber bands.

Finally, a tip I learned from DD is to consider adding a transfill whip to your dive bag. This way if you have an accidental loss of gas on the pony you can top it back off with your main tanks.

I actually have a set up similar to DD as far as my pony. Being that we share a common interest in diving activities and the fact he has a ton of experience I decided not to try and create an unproven configuration. Basically, my 19 is tank mounted upright with a Highland Tank Mount, Button SPG, (It doesn't matter I if I can monitor the gas, it's a 19. If I'm on it I'm making a direct/safe ascent to the surface and if there's still gas, I'll hang at 10 feet until I empty the bottle and then surface.) 30" hose under my right arm with the second stage on a 90 degree swivel and necklaced. I added an AIR2 to my rig which now serves as my second if I'm air sharing.

As far as skills... You know the drill.... Practice.

Anyway, long post I know. Hope something in it helps. And with my limited experience, if something I said is inaccurate... Give it a minute and someone will correct me.