Pony Bottle: Valve On or Off while diving

[tbone1004]

So a pony bottle is not to be used for gas planning purposes, but rather emergency purposes only. Planning has nothing to do with a pony bottle; it is there for one purpose and one purpose only, that one's primary source of air is no longer working due to a failure. Running out of gas is not an equipment failure, but poor gas management. One's pony bottle is not there to compensate for one's poor gas management skills, although it will save your ass in that event. Having doubles or sidemount, one still has to plan your gas management. Equipment failure can happen with any rig, and a pony btl is insurance against an equipment failure.

Where did I say it's part of gas planning? I just said it needs to be planned for to make sure that it's big enough to do its job.

 

[Gandalf-the-Diver]

Don't use pony bottles, proper planning prevents the need for pony bottles.

You also said the quote above. A pony is there for the un-planned for emergency.

 

[Wibble]

Solo divers must have redundant gas. Hence twinset, sidemount, or single with redundant backup a.k.a. Pony

 

[andrespp]

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.

 

[Celt]

Spare air, mask, fins, torch, smb, reel, knife, four second stages, computer, alerts bells and whistles. A scooter and spare batteries and a spare boat coming behind you. How do some get to go diving.

 

[Gone for diving]

Pre charged, then off,
After jumping in the water possibly opening it on the way down,
(Reaching valve is a must,)

But I will only normally carry a 40cu,
If myself or buddy has borderline pressure left for second dive,

 

[Soloist]

You also said the quote above. A pony is there for the un-planned emergency.

My thoughts exactly, unless your dive plan includes a catastrophic failure! When I carry a pony solo diving the “plan” is to NEVER use it.

 

[Divin'Papaw]

My thoughts exactly, unless your dive plan includes a catastrophic failure! When I carry a pony solo diving the “plan” is to NEVER use it.

+1 It is my "buddy gas" since I have no buddy. Not part of any plan, purely there to get me to the surface safely in the event of a catastrophic failure (tank o-ring blows, low pressure hose blows, reg fails closed, etc.). All HIGHLY unlikely, but when I'm solo diving I want that redundancy because sometimes sh&t happens.

The only times I ever use it are (1) practice and (2) DSMB inflation. I always make sure I have ample volume in my pony (I sling an AL40) at the start of any solo dive beyond safety stop depth. I also use a rock solid reg of equal quality to my primary reg. If I need it, I want to KNOW it will work. I also have it serviced regularly as well just like my primary.

 

[Wibble]

Pre charged, then off,
After jumping in the water possibly opening it on the way down,
(Reaching valve is a must,)

But I will only normally carry a 40cu,
If myself or buddy has borderline pressure left for second dive,

You must carry whatever you require for the dive; that may be more than an ali40.

Bluntly, it's not dissimilar to planning a CCR bailout -- that is fully redundant gas that is not required during a normal dive.

Obviously if diving "deep", you'd be using a twinset/sidemount and carrying your redundant gas within your existing gas supplies.

Talking of which, deco cylinders are normally dived pressurised but turned off -- as a precaution against breathing hyperoxic gas at depth.

A bailout stage is kept powered on at all times so you can grab it immediately should some sudden and drastic event occur.

 

[Gone for diving]

You must carry whatever you require for the dive; that may be more than an ali40.

Bluntly, it's not dissimilar to planning a CCR bailout -- that's fully redundant gas that is not required during a normal dive.

Obviously if diving "deep", you'd be using a twinset/sidemount and carrying your redundant gas within your existing gas supplies.

Talking of which, deco cylinders are normally dived pressurised but turned off -- as a precaution against breathing hyperoxic gas at depth.

A bailout stage is kept powered on at all times so you can grab it immediately should some sudden and drastic event occur.

I normally am inside deco limits,
I dive twin 72s, so I am not normally worried,
But sometimes it's nice to have extra air,
When on a tiny boat, second dive on the tanks to 110ft in 8*C water.
It's a cushion so I call it a pony, but could be considered stage, for if anything goes wrong,
( I carry it in sidemount configuration)
I air it up to check it, shut it off so there is no chance of free flow, when jumping in etc,
If I am low on my back gas, I will turn it on,
I have dove sec dive 110ft strictly on my 40cu ft. (With back gas) Its actually quite impressive how long it lasts but you have to be very relaxed,