Is there a valid reason for a pony bottle

[doctormike]

No, There could be a big difference in complexity, resolution of problems during an emergency and also task loading. Independent doubles require careful gas monitoring and regulator switches. In the event of say a first stage problem or failure or leak or o-ring or hose compromise, it might be quite difficult to immediately determine which of the two tanks has a problem (behind your neck and out of sight). Conversely, with a single tank behind you, a failure behind your neck is going to be associated with just one tank and you probably don't need to be diagnosing it or fiddling with valves or contorting your shoulders and elbow..

With a slung pony, when the primary tank becomes a problem, you reach down to a reg and valve that you can easily see and manipulate and utilize in less than 10 seconds and then go up. You don't need to necessarily diagnose what is going on behind your head. And if the pony reg has a problem, it is much easier to feather the valve off and on with a slung pony, compared to a tank behind your back.

I think the complexity of independent doubles (and definitely manifolded doubles with 3 valves) is quite different than a slung pony. They are not necessarily equivalent in several regards.

edit: Now a back mounted pony - that would be more similar to independent doubles.

Ahhh... I see! They ARE different things...

So, you would say that for Max's deep dive mentioned upthread - given the context and scope of this discussion and forum - you would recommend that he use a pony instead of his isolated doubles? Maybe an 80 on his back and a slung 80 on his side?

 

[Fastmarc]

not that ill use a pony every dive or maybe i will who knows. depends on dive buddy and dive situation. maybe that makes me one of your two sides.

One thing I was worried about when I decided to add a pony is how more complicated it would make my dive routine. What I have learned since is that it really doesn't.
I can think of no excuse for not diving with one with regards to inconvenience.

 

[NAUI Wowie]

As a matter of interest who participating on this thread has had to share air in a full-blown emergency. I am not talking about practising air shares, they are easy, but having to help a diver in full blown panic who was clawing for the surface. This doesn't have to be your buddy but could be another diver in a group who picks you to mug as has happened to me. He was not even a member of the group I was with. Maybe if he had a pony he would not have put me at risk.

I had to share air personally. reg stated 650 psi but was completely empty. I calmly swam over to the DM , made the throat slash gesture, he looked at me again I was totally calm and slit my throat again and he handed me his octo. he then grabbed my primary tried to breath out of it and looked at it in surprise.

When on the boat he said it took him by surprise as I was so calm. I didnt have to worry as I was staying close to him and another and can easily hold my breath a long time while not going up or down. This was btw my third dive ever. next reg on next dive was also cr@p and malfunctioning.

 

[NAUI Wowie]

Wouldn't it be even better if they had been able to avoid any Oh S*** moments? After all, having a couple of Oh S*** moments means that their judgment had lapsed at least a couple of times...

not true. Ive had a few, more than two oh s... moments. all due to gear not my own or in one instance a reg a buddy gave me that i had serviced and its still slightly malfunctioned. wasnt getting enough air at 100 feet. didnt notice until i got down there. Co2 loading and exertion added up instantly and when I was in front of dive buddy i was pretty woozy. My fault on that last one? maybe. but i went out after my car was totalled and bought the best reg set I could find. and no im not a walking accident waiting to happen, my car was hit parked on the street by a druggie doing 60 in a 25 residential.

 

[AdivingBel]

When faced with an instabuddy I show them my pony and explain that is my redundant air source and point out that I am theirs but they are not mine.

It's not the pony or insta-buddy, it's you. Why would you do that? Why not just show them how your pony works and how you would deploy it in an emergency. Then just go dive with the pony and act like you've been there before. It might impress them by showing them something new. Why act like an a$$hat to a perfect stranger? They might be the best dive buddy you NEVER had.

 

[grf88]

It's not the pony or insta-buddy, it's you. Why would you do that? Why not just show them how your pony works and how you would deploy it in an emergency. Then just go dive with the pony and act like you've been there before. It might impress them by showing them something new. Why act like an a$$hat to a perfect stranger? They might be the best dive buddy you NEVER had.

Because I have had too many instabuddies expect me to chase after them the entire dive.

 

[MaxBottomtime]

You said isolated doubles. Did you mean manifolded doubles? Not being snarky, might be another term for the same thing. I was assuming you meant doubles that you were diving as independent doubles (i.e. isolator closed).

Isolated doubles: Two scuba tanks, with a single first stage and one or more second stages.

Single tank and pony: Two scuba tanks, each with a single first stage and one or more second stages.

So if you are diving "deep" (remember, we are in basic, so no references to deco), you feel that isolated doubles are appropriate, but a pony tank isn't?

Manifolded doubles with an isolator valve. For the dives I was making, double 120s and stages were necessary. I wasn't carrying around any "extra" gear on those dives. A pony would have been a fifth tank in the way.
Although two posters here keep harping the same thing over and over, I don't care if anyone wants to use a pony, just not on my boat. I feel they are a redundant piece of gear for a situation that is so rare that it will likely never happen to anyone involved in this thread. If it brings you peace of mind, haul it along with you on every dive.

 

[NAUI Wowie]

On the your point of equipment failure likely hood - I can't argue with it. I run monthly weekend dives for a group of friends and have for 5 years. We keep records or dive stats and "incidents", so looking back I can tell you that with a combined total of 5342 individual dives teh failures have been as follows

1 x LPI inflator runaway (mine)
4 x hose bursts on the surface while turning tanks on
6 x O-ring failures on the surface - again found when turning tanks on.

So yeah nothing of consequence. And 1000's of rec dives are made daily with basic rental gear without incident.

But if you do have a redundant system - my view that it shoudl be big enough to handle your worst case (being sensible). My figures for instance assumed that a 13cf held 13cf - but as you pointed out an 80 only holds 77cf. I want to not have to worry that my redundancy is just enough.

But I understand that you have limitations on travel and you could argue that some is better than none. Again fair point as long as when people do the maths they understand the limitations of any compromise they've made and act accordingly.

This is why I travel with Sidemount. I always have way more gas than I need on each dive, and without the hassle of lugging a pony cylinder on an aircraft. I've never had issues with my SM at the destination but we're able to choose "grown up operators"

lol do you dive in mexico? ive had plenty of junk regulators in mexico ....maybe everything is well maintained in Dubai but NOT in mexico lol, their equipment with many dive centers is make sure its working well enough to get you into the water. after that they already have their money.

 

[MichaelMc]

I feel they are a redundant piece of gear for a situation that is so rare that it will likely never happen to anyone involved in this thread.

Hmmm. If it is so rare to need a pony, why is it the principle piece of redundant gear recommended by the Padi recreational Self Reliant diver class?

 

[AdivingBel]

Because I have had too many instabuddies expect me to chase after them the entire dive.

Well...it's probably good you dive with a pony. If you treated some of the folks I dive with like that, your solo dive would start before the boat stopped. I get being careful, but treating other divers like that...I'm surprised you can find a mask strap that fits. Good luck & safe diving...