Do you dive with your pony valve turned on? Off?

[Colliam7]

I've seen one of those in-line valves explode on the boat. No damage but a lot of noise and loss of gas.

Interesting. I wonder if others have had similar experiences. Was this with the specific OmniSwivel device, or another in-line shutoff unit?

If you use an inline shut off for a stage bottle, are you supposed to add an over pressure relief valve to the first stage as well? If you got IP creep with the valve off, will the hose be over pressurized?

Great question, and point! Since the (one) second stage on a pony is a de facto 'over pressure relief', with the shut-off valve in place, in the absence of another relief system, the LP hose becomes the OPR.

so I am curious what the expert technical dive instructors say about this stuff?

For technical diving (not for recreational pony bottle use), I suspect most would say - unnecessary, represents an additional point of failure, don't use. That would be my individual 'technical' answer. But, I am still curious about the device - perhaps a little less so now after reading of your experience, I must admit. It would make sense for the valve to be constructed to 'fail' - to open - above a certain pressure, but I didn't see anything in the specs on the OmniSwivel website, so I sent them an email inquiry. It will be interesting to see what they say.

 

[DaleC]

I am in the on camp.

A pony is not a stage bottle and tech procedures are not rec procedures. Stage bottles are accessed in a non stressed, deliberately timed manner where you remain on back gas while you trace the line to the bottle, check contents and then switch. Ponies are emergency bailout gas supplies that may be accessed when you, or someone else, have no backgas to breath.

The off/charged camp also doesn't address the occasional need to purge the reg before breathing - there goes that gas.

Individuals changing the paradigm should consider what effect that may have.
In the rec setting all gas is on because that is what other divers, including myself expect and are taught. No rec agency teaches an intermediary step between signaling OOA/LOA locating and the donation of a reg. That is the standard, just as having an alternate is the standard over buddy breathing. I may be able to buddy breath just fine but the other divers around me probably don't understand - just as they won't understand a reg in the rec setting being dead. If they breath a dead reg and get no gas they will assume it is OOA and either remove your primary or bolt to the surface. Hopefully the hand fending them off will not be the one trying to turn the pony gas on. Some also advocate removing the octo from backgas and using the pony as the alternate (which I do when diving vintage). In that case you would then have your octo turned off.

Probably there are better divers than me but I just don't want to devote bandwidth to securing a functional airsource in a stressed situation. I'm probably using that to assess the situation and evaluating exit options. The transition between airsources (which aren't different MOD's in the rec setting) should not be an event in itself, as it is in the tech realm.

 

[Crush]

I am in the on camp.
...

The off/charged camp also doesn't address the occasional need to purge the reg before breathing - there goes that gas.

I am not arguing against your choice of on. I'd just like to point out the obvious (to the OP) - all diving skills are perishable. If I dive with a pony, I practice switching to the pony and then stowing it at the beginning of the dive, then a few times during the dive. I don't think about it, I just do it. Having a transfer whip is handy so that I can charge my pony from a new tank between dives.

 

[uncfnp]

DaleC. I look at it a little differently. For me, a diver with a pony is not entirely in the pure rec world and a few modifications to the traditional recreational paradigm is not inappropriate. Many divers with ponys are diving in more a self reliant mode and may not be buddy diving at all. If so and its not a usual buddy aware of the gear configuration, a predive discussion is obviously needed.

For me, although 99 percent of my diving is solo or same buddy, I still dive with a configuration to donate my primary and go to a bungeed second for myself. My pony is there for MY gas emergencies and as such I practice deployment often and I know my gear and can deploy in seconds.

If an OOG situation ever happened and it was appropriate, I would probably then donate the pony so that we could both then make the ascent together in what I think would be the safest way possible for both divers.

But I admit, this is purely theoretical on my part. I have never been part of an unintentional OOG situation.

 

[Hatul]

Definitely on. If things go to crap I don't want to do more than pull the reg from the octo holder and breathe. Freeflow is obvious because it's on the front of my right shoulder. Knowing that I don't have to fiddle with a valve is calming and is one less thing I have to think about. Lower task loading is good. In an emergency it's great.

I agree. I also keep mine slung on the right side, so if there's leakage I can see it. Also the button SPG is turned so it's visible at all times.

If you do keep the valve off you should make sure the system is at least pressurized because the pressure provides part of the security between the reg and the valve.

 

[Kairoos]

Interesting read for sure. I just bought a pony (30 cu) and I'm going to sling it, so I think I'll leave it on. I think in the case of a real emergency I would rather it be on and ready to go. 30 cu is a good amount of air, so I'm not worried about the occasional freeflow.

 

[Grocio]

Off but pressurised, here.

 

[raftingtigger]

No one is recommending the following, but since it accidentally happened to me I will share: OFF and UNcharged is bad! My sidemount tank dropped off my kayak into 60' water and was OFF and supposedly charged. When it was recovered it was OFF an UNcharged. The first few breaths off that tank after the valve was turned on was a high percentage of water and low percentage of air. Definitely NOT something you want from a reg in an emergency. Since in my case it wasn't an emergency, and I had several other 'working' regs immediately available (and used) it was more like amusing. I did clean and rebuild the regulator afterwards ;-D

 

[dumpsterDiver]

Interesting. I wonder if others have had similar experiences. Was this with the specific OmniSwivel device, or another in-line shutoff unit?Great question, and point! Since the (one) second stage on a pony is a de facto 'over pressure relief', with the shut-off valve in place, in the absence of another relief system, the LP hose becomes the OPR. For technical diving (not for recreational pony bottle use), I suspect most would say - unnecessary, represents an additional point of failure, don't use. That would be my individual 'technical' answer. But, I am still curious about the device - perhaps a little less so now after reading of your experience, I must admit. It would make sense for the valve to be constructed to 'fail' - to open - above a certain pressure, but I didn't see anything in the specs on the OmniSwivel website, so I sent them an email inquiry. It will be interesting to see what they say.

I don't know what an omni swivel device is. I have only seen a few of the in-line shut off valves and didn't pay them a whole lot of attention (other than when i used them on a deco reg with a hose to the boat.

It just seems like you are adding two new failure points.. an OPV and the valve and I am not sure it is worth the trouble for a pony bottle. It also adds some complexity, because you could have the tank valve off and the in line off, the tank valve open and the in-line off, you could have the tank valve open and the in-line open.

If a very scared diver sticks the reg in their mouth and it delivers no air, they could then slide the shut off valve from open to closed, still get no air...then they open the tank valve and get no air (because the in-line is off), then they could get confused and shut the tank valve off (trying to get air) and then they slide the in-line valve to the other position and STILL get nothing. Then they go through a whole nuther series of twists and slides while starving for air and being scared and confused? ...I was always having to re-learn which way the in-line valve worked on that deco hose...

People on here claim that a pony bottle adds too much complexity for a recreational diver (without a lot of training) .. well using an in-line valve and playing around with the tank valve certainly could add some complexity. Is it that hard to leave the pony on and watch and listen for air leaks????

 

[JohnN]

People on here claim that a pony bottle adds too much complexity for a recreational diver (without a lot of training) .. well using an in-line valve and playing around with the tank valve certainly could add some complexity. Is it that hard to leave the pony on and watch and listen for air leaks????

My thoughts are that with "only" a 19 cuft pony (because I want it to travel on airplanes), there is not an abundance of "extra" gas if the secondary starts to free flow. Besides, the pony is only for situations where poo has impacted the fan, if I got a freeflow on the pony's secondary and lost much gas, all those lovely calculations about how much gas I'd have available go out the window (or up the water column). I would need to scrub the dive (diving solo).

Since the pony is for me, I'm not sure why I'd be 'playing with the tank valve' (it would be on just like my back-gas), and sliding the in-line valve open seems much easier than opening the tank valve (mine takes 4+ turns). Yes the OPV could fail, I haven't seen any mention of a quality slide-valve failing, so for me that event seems a reasonable risk.