Stage and pony bottle regulator question

[DaleC]

I side-sling a 30 cu ft pony on my left, prime it, and leave it off. You have plenty of time in an OOA situation to turn the valve on, reduce the likelihood of free flows, and there will be enough air to start the purge when you reach for it.

I find side-slinging easier than back-mount when changing tanks on repetitive dives, and it doesn't get in the way of my picture taking, but I'm a crappy photo/videographer.

Curious how you know this? Which hand do you donate the reg with, which hand do you turn the valve on with. Is it the same hand. If so, which do you do first.

 

[Agility]

I'm going to have a Dive-rite cold water kit installed when I get it oxygen cleaned soon so that should take care of the water inside the first stage.

The cold water kit will not prevent water entering the fist stage via the hose if the purge button is pressed while unpressurized (and under water)

 

[Crass3000]

But, why do you conclude that water entered the first stage (through the second stage and the LP hose)? I am not disagreeing, just trying to understand the basis for the conclusion.

I have dove with the tank unpressurized probably 20 times and down to as deep as 185ft (not a frequent depth for me but that was about the max). I just noticed water draining out of my second so I assumed since I was dumb enough not to pressurize them that the water likely went into the 1st stage.

I'm having the reg and bottle oxygen cleaned very soon so hopefully there will be no issues. I just need to be smarter in the future.

---------- Post added August 2nd, 2013 at 01:40 AM ----------

The cold water kit will not prevent water entering the fist stage via the hose if the purge button is pressed while unpressurized (and under water)

I'm aware of this. Without the kit the reg is good in "cold" water down to 50F. The water I dive under a second thermocline is in the mid 30sF. The kit is to prevent freeflow due to frozen first stage.

 

[Peter69_56]

The 'tech' approach, with deco cylinders, is to pressurize the cylinder and then turn it off. This is designed to prevent loss of critical deco gas, whilst also providing a defense against accidentally breathing that gas below its maximum operating depth. Technical divers in training receive ample instruction and practice on the procedures to identify, turn-on and access those cylinders. A properly competent technical diver should have a high-level of fluidity with valve manipulation and should also be expected to remain calm and controlled during brief periods of air depletion.

In contrast, a 'pony' regulator functions as an emergency air source. A recreational diver should not be assumed to have a high-level of fluidity with valve manipulation and should also not be assumed to remain calm and controlled during periods of air depletion (accident statistics reinforce against such assumptions). For those reasons, it may be prudent to leave the pony cylinder fully-on throughout the dive - providing immediate and unrestricted access should it become necessary.

Technical divers who use 'pony' cylinders on recreational dives might opt to operate them as per deco cylinders. However, they will be well rehearsed in the swift actions needed to access a pressurized/shut-off cylinder and should be confident to remain calm during that process. In this case, the benefit is derived from following a consistent protocol across all manner of dives (tec/rec) and the ingrained muscle memory response that they have achieved.

Totally agree

 

[ajduplessis]

Curious how you know this? Which hand do you donate the reg with, which hand do you turn the valve on with. Is it the same hand. If so, which do you do first.

Cylinder on the left: Donate with right hand (aross your chest) and open valve with left hand all in single action.

 

[DaleC]

Perhaps. I have seen a lot of bottles bungiied in such a way that a right hand deploy would not be possible though (when slung on the left).

I'm not such a good diver so I tend to configure in such a way that even a dope can handle things. I also know it is easier for me to look at an SPG occasionally and watch for 20-40cuft of air escaping from my left armpit when not stressed than it is to worry about deploying a reg to an OOA diver and turning it on when stressed.

After a few dives I have never seen a pony lose a significant amount of air without notice. No one has ever come up and said "I lost all the air out of my pony on that dive". I have seen a handful of crappy reg deployments however.