Pony Bottle: Valve On or Off while diving

[scubadada]

Sorry, I forgot to answer this question, sling the correct size pony for your diving and gas consumption and leave it on, there.

 

[Marie13]

I would like to know as well the reasoning for hanging diagonally

Probably used by those people who have a jacket BC and lack D rings in the proper places to sling. I see instructors with this at the local quarry.

 

[TooCold]

Reading through this thread, I see quite a lot of posts givng very reasonable and well thought out reasons for both "valve on" and "valve off". There are risks either way to balance against the benefit (gas available in time in an emergency). I dive OC, but for me, the risk at the top of my list is not having those first few breaths available fast enough (like the rationale for bailout on CCR), so my choice is to go with the valve open. Then mitigate the consequential risks (like accidental freeflow).

My thinking is heavily influenced by a near-miss I had early on, maybe my 5th dive after AOW, which comes to mind every time I'm gas planning. So, noob diver, using all rental gear except mask snorkel fins, and the gear was generally pretty "worn". But what did I know about checking out a shop before deciding to dive with them? Guided group dives of around 8, noob instabuddy.

So first dive of the day, max depth 24m. About a minute after descent my 2nd stage failed, and I got nothing but water. Lots of water. I choked, my throat spasmed and started coughing. I just barely managed to suppress the reflex to inhale after cough (try it sometime) while grabbing my octo. That was the beginning of a long session of coughing, gagging and retching, and I'm sure my SAC rate was through the roof. When I consider a pony, solo, I'm convinced I wouldn't have survived that scenario with the valve off. So for me, I think that delay can be deadly, and should be minimized.

 

[NW Dive Dawg]

Reading through this thread, I see quite a lot of posts givng very reasonable and well thought out reasons for both "valve on" and "valve off". There are risks either way to balance against the benefit (gas available in time in an emergency). I dive OC, but for me, the risk at the top of my list is not having those first few breaths available fast enough (like the rationale for bailout on CCR), so my choice is to go with the valve open. Then mitigate the consequential risks (like accidental freeflow).

My thinking is heavily influenced by a near-miss I had early on, maybe my 5th dive after AOW, which comes to mind every time I'm gas planning. So, noob diver, using all rental gear except mask snorkel fins, and the gear was generally pretty "worn". But what did I know about checking out a shop before deciding to dive with them? Guided group dives of around 8, noob instabuddy.

So first dive of the day, max depth 24m. About a minute after descent my 2nd stage failed, and I got nothing but water. Lots of water. I choked, my throat spasmed and started coughing. I just barely managed to suppress the reflex to inhale after cough (try it sometime) while grabbing my octo. That was the beginning of a long session of coughing, gagging and retching, and I'm sure my SAC rate was through the roof. When I consider a pony, solo, I'm convinced I wouldn't have survived that scenario with the valve off. So for me, I think that delay can be deadly, and should be minimized.

My opinion is that in your particular scenario the Pony valve being off or on is really not a factor. Even with the Pony "available" you still should have an "alternate" air source or "octo" to access gas from your primary system. For me...and maybe it's just me.....my Pony is ON and ONLY there in case of a total failure of my entire primary system. My Pony system is 100% and completely redundant. My feeling is that the odds of both completely redundant systems failing on the same dive are astronomically low.

 

[TooCold]

My opinion is that in your particular scenario the Pony valve being off or on is really not a factor. Even with the Pony "available" you still should have an "alternate" air source or "octo" to access gas from your primary system.

What I said was:

... maybe my 5th dive after AOW ... So, noob diver, using all rental gear ... Guided group dives of around 8, noob instabuddy.

so no pony; and:

... while grabbing my octo.

It's all I had avaialable anyway. And on the topic of this thread:

my Pony is ON and ONLY there in case of a total failure of my entire primary system.

which is what I said, so we agree.

 

[Gandalf-the-Diver]

Probably used by those people who have a jacket BC and lack D rings in the proper places to sling. I see instructors with this at the local quarry.

I have a Scubapro Hydros pro back inflate bcd, D Rings in all the proper places. I sling my 30cu diagonally, primarily so there is equal weight distribution between both sides of my body; eliminating the need to counter-balance. If I ever had to hand it off to a distressed diver, my trim would not be out because of counter-balancing.

 

[tbone1004]

I have a Scubapro Hydros pro back inflate bcd, D Rings in all the proper places. I sling my 30cu diagonally, primarily so there is equal weight distribution between both sides of my body; eliminating the need to counter-balance. If I ever had to hand it off to a distressed diver, my trim would not be out because of counter-balancing.

I would strongly recommend you reconsider that plan….
Also an al40 wouldn’t cause the off balance issue than an al30 does but while cross clipping may solve the feeling of being lopsided it creates far more real issues in your equipment configuration

 

[HKGuns]

I REC dive a slung AL30 pony, gas off with the same brand regulator as my primary. (Atomic)

 

[CaptainChris]

I have mine "charged" but valve off. I use a 7L aluminium tank side mounted when i dive with a 15L single tank for 30m dives. I'm usually guiding dives this way so if a customer gets an OOA I can give them the 7L and send them up safely and do the same myself without using my Octo and having a stressed diver sucking all my air

 

[Marie13]

I have a Scubapro Hydros pro back inflate bcd, D Rings in all the proper places. I sling my 30cu diagonally, primarily so there is equal weight distribution between both sides of my body; eliminating the need to counter-balance. If I ever had to hand it off to a distressed diver, my trim would not be out because of counter-balancing.

There’s no need to counter balance. I had an AL30 slung on my left side for a couple of years before I went to an AL40. The 40 hung better but the 30 wasn’t an issue. But then you’ve got an expensive poodle jacket. You may *think* you’ve got D rings in the proper place, but compared to a BP/W, who knows?