Pony Bottle: Valve On or Off while diving

[gamon]

I back mount my 30cf pony bottle, it's strapped to my main tank.

Behind me, out of the way, I don't even know it's there, doesn't interfere with my camera rig that is attached to my two shoulder D rings.

Don't know why some divers discourage a back mounted pony, one went so far as to call it "an abomination" but I'll just disagree and consider them to be ill informed and lacking the experience of even trying to use a back mounted pony bottle and therefore not knowing any better.

I offset the pony with 3 lbs of extra weight on the opposite side, no big deal.

It's always valve-on, and it's got a transmitter that I read with a second computer on my left wrist.

I "use" it on every dive- in so far as that I consider it a redundant emergency gas source during most of the dive and towards the end I consider it to be my reserve tank, so I can draw my main tank down to about 300 psi, therefore extending almost every dive.

 

[happy-diver]

My personal preference is to have the valve open, but the second stage being fitted with a freeflow control device that will be closed when 2nd stage is not used. This prevents the 1st stage and pressure gauge to be flooded as well as any gas leak coming out.

Then, in order to prevent accidents in case of a malfunctioning 1st stage, an overpressure valve is to be installed in the 1st stage.

 

[Hoyden]

I believe, practice, and teach charged but off. If I need to switch to my bailout I want to be sure that it has air. I have no concern about water intrusion to the first stage and have done wet reg swaps (in freshwater). I do have concern that I might need my bailout and find it empty. I have also never seen any training agency that recommends just leaving it on.

YMMV,

Jackie

 

[Divin'Papaw]

I've been rethinking my process. Honestly, I've done so many dives with a deco bottle or a pony staged that I do it second nature. I had to actually "think" through what I do as pure muscle memory. I need to revise what I posted earlier. I leave mine charged but off. However, I do "feather" the valve on then off several times during the dive to ensure it stays charged. If I'm shooting a DSMB, I will then turn it on near the end of the dive, use it to inflate the DSMB via a short inflator hose, and then leave it on.

That process is so second nature I had to actually force myself to recall the process I follow without even thinking.

 

[Bigbella]

"Valve On or Off while diving?"

That would depend entirely upon the regulators and their sensitivity. When I use Cyklons (which are typically tuned just-short of free-flow), I typically pressurize those pony bottle(s), but switch those valves off (if side-slung), especially while diving off of boats or even through heavy surf; or, alternatively, have used Omni-Swivel shut-off valves, with the tank open. In the case of Jetstreams, the valve always remains open, since those second stages possess a very effective "sensitivity" switch, which haven't ever free-flowed or leaked -- even after some questionable "don't try this at home" rocky entries, off of Big Sur . . .

 

[Gareth J]

I believe, practice, and teach charged but off. If I need to switch to my bailout I want to be sure that it has air. I have no concern about water intrusion to the first stage and have done wet reg swaps (in freshwater). I do have concern that I might need my bailout and find it empty. I have also never seen any training agency that recommends just leaving it on.

YMMV,

Jackie

When I used a pony, it was always back mounted and turned on.
There was a period when I was diving twins and a pony of 50%, back mounted (way back in the day when computers only used air for calculating deco and Nitrox was like rocking horse ****). Then the pony was inverted and shut off until required on the stop.

Any time I carry emergency gas, either a back mounted pony or a bailout side slung, it is always turned on. Any time the gas is toxic at depth, the first stage is pressurised then switched off ( I might re-pressurise the first stage in the water at depth, but I will always make sure the cylinder is off). Only turning on a potentially toxic gas directly before it is to be used. Even travel gas is shut off once I switch to the bottom gas, only turned back on as I approach the switch back to travel.

I don't know of any agency teaching CCR that would allow the bailout to be off! There is no difference if you are OC or CC, if it is an emergency gas it should be on and ready to use.

I much prefer back mounted over side slung, but that is only really viable with 3 or possibly 5 litre cylinders, after that it is always side slung. I reckon 90% of the diving I do means I am carrying at least one side slung stage.

 

[Nemrod]

Maybe set the second stage to pre-dive or detune it a bit (with the adjustment knob if available) to reduce the likelyhood of a freeflow. How would a free flow be missed if the reg is necklaced or secured near the valve?

James

 

[Wibble]

Turn the lever back on the second stage.

 

[TOMWIEDEMAN]

Been musing around the idea of backup/redundant air in the form of a pony bottle for a while now and I've been wondering a few things.

Let's first start with a couple of givens:

1. 13 ft^3 bottle
2. Mounted on the main tank or on a Zeagle Zipper attachment on the BC (I have a ranger LTD)
3. Stage Kit type rigging
   1. SPG
   2. DIN first stage
   3. Second stage with long hose and retainer band

For some reason one potential and routine problem that comes to mind is sudden free flow of the pony second stage, whether at the surface or just because it doesn't like the position, or losing air through an incipient leak through a loose fitting or the like.

My gut says that the pony tank valve should remain closed until needed. Of course this would mean having immediate and ready access to the valve which in turn means the tank should likely be mounted valve down.

Am I barking at the moon or is there some merit to this thought?

I'm new to backplate BCD, XDeep Zen NX, and looking for suggestions on mounting 13 cf pony bottle and reg, which would always be on during any dive. Use of bottle for emergency only. My only use to date was the result of ruptured reg hose at 80 ft, cold water, beginning assent. Lost air almost instantly. My buddy carried a spare tank, enabling normal assent. I've been a believer since.

 

[Gandalf-the-Diver]

I'm new to backplate BCD, XDeep Zen NX, and looking for suggestions on mounting 13 cf pony bottle and reg, which would always be on during any dive. Use of bottle for emergency only. My only use to date was the result of ruptured reg hose at 80 ft, cold water, beginning assent. Lost air almost instantly. My buddy carried a spare tank, enabling normal assent. I've been a believer since.

I am a firm believer of slinging my pony diagonally across my chest. I did this with a 13cu for 70 dives. (I use a 30cu now, slung the same)