Recreational Pony Bottles, completely unnecessary? Why or why not?

[grf88]

Hartattack bowed out of the thread, but I do not recall him taking that position on doubles.

Each claimed that redundancy was not necessary so I just took it to their logical ridiculous conclusion. I believe someone else should either read the thread or otherwise bow out. I find it quite remarkable the number of people who use manifolded doubles with a high degree of redundancy would try to discourage others from using a redundant system and it is this discouragement that I take issue with. Use a pony or don't but do not belittle those who do by claiming they are incompetent divers who don't understand gas planning.

 

[boulderjohn]

Each claimed that redundancy was not necessary so I just took it to their logical ridiculous conclusion.

As I understood his argument, Hartattack said that redundancy was not necessary as long as you watched your gas carefully and always began your ascent with enough gas to ensure that you and another dive sharing air could ascend using the GUE ascent profile. He said (incorrectly as I understand it) that such a profile would require two divers to take 9 minutes from 80 feet.

Well, I think he has a point. If you always cut your dive time in order to begin your ascent with an enormous amount of usable gas, the odds of your needing a pony are pretty slim.

 

[grf88]

As I understood his argument, Hartattack said that redundancy was not necessary as long as you watched your gas carefully and always began your ascent with enough gas to ensure that you and another dive sharing air could ascend using the GUE ascent profile. He said (incorrectly as I understand it) that such a profile would require two divers to take 9 minutes from 80 feet.

Well, I think he has a point. If you always cut your dive time in order to begin your ascent with an enormous amount of usable gas, the odds of your needing a pony are pretty slim.

I pointed out that regardless of how much gas was in the cylinder it was not much use if it became unavailable.

 

[Nemrod]

Agree with all of the points. I have never felt the need for a pony (even though several dm buddies use them on every dive), have always relied on buddies, but have a few things that are making me reconsider some sort of redundancy. My normal buddy is cheap and does not maintain his gear at all. He simply buys whatever cheap gear he can find a "deal" on. I didn't really know this until we were doing our Rescue class together and I needed to use his octo. It breathed fine out of the water, but at depth, would gurgle some water, and was really hard to breathe. Turns out, it had a tear in the membrane (or whatever the piece is inside the octo). It was not a big deal, because we were in the pool at the time, but it just made me understand that relying on a buddy (any buddy really) is more risk than knowing what you have, and how well you maintain it.

I just completed sm training, and waiting for my bcd to arrive, and plan to work on that more now for redundancy for deeper dives to have a fully redundant system and be used to using it. If I wasn't going that route, I probably would have looked into getting a pony to use just for the added piece of mind, hoping to never actually need it.

I understand and that is why I mentioned that generalizations fall apart when specifics come to bear. In this case, you say your buddy is not well equipped, has unreliable gear and essentially cannot be counted upon. But, you enjoy his company, and want to continue the diving and other relationships with the person, so you are left with a choice, buy him some nice gear, wink, wink, or become more self sufficient. You are between a rock and a hard place. Friends are hard to find, come with a price and are not easy to keep sometimes and you value this relationship. I guess you need a pony bottle, or something .

James

 

[Wibble]

I am of the mind that in recreational buddy diving, no pony or redundant air supply is needed as the buddy system provides the redundancy. Exceptions to any generalization when getting specific of course always exists. An example could be photo divers, teamed up, but playing more with their cameras than paying attention to each other can and often do drift apart further than would make possible a practical air share quickly during an OOA emergency. In such case, a pony bottle might be wise or perhaps wiser to stay close(er) to your buddy team mate. Another example is group diving where divers are just together, all of them a potential buddy but none specifically assigned to each other, yes, it happens often. I can see a pony bottle useful.

But, if a diver, feels they want to carry a redundant supply, go ahead. Regardless, if you are a part of a buddy team, there is a responsibility inherent to your buddy and to the buddy system and chief among these responsibilities is providing a redundancy to each others air supply. Solo diving is a different world, the SDI Solo manuals provides guidance there and per it all solo diving should have a fully redundant air supply sufficient to the dive. Since this is not a solo topic thread, I will leave that as it is except that, sufficient is still applicable. If your going to carry a redundant supply, it needs to be sufficient to the purpose! Taking the ubiquitous aluminum 80 cf tank, it is reasonable to think that 1/3 of your air supply might be enough for an emergency. That would be 27.7 cf I think. That leaves a choice between a 19 and a 30 cf pony. For me 60 to 80 feet is the cutoff on deciding 19 vs 30. Availability also impacts the choice.

If desination diving, hauling pony bottles or setting up twinsets is not always easy to accomplish. Possible usually, but easy no. In such case, there is the buddy system properly executed. The buddy system works and IMO obviates the need for self redundancy.

If buddy diving, then buddy dive, in the fullest sense.

James

Yes-ish.

But this really does depend upon the dive conditions. Diving in poor visibility in a current on a wreck where there's a sporting chance the buddies get separated, diving with a reserve source of gas is an easy way to turn a life-threatening incident into an inconvenience and a great story back on the boat.

Hence in some locations it's very much the exception for someone to dive with a single tank only. In my early UK dives I literally held on to my buddy in really poor conditions to avoid separation. Didn't dive a single for long; moved to a twinset as soon as I could (and could do the shutdowns).

 

[grf88]

Conclusion: in 2 out of 3 cases, pony was the trigger of the incident (yeah I know its the diver who makes the error).

The incorrect use of any piece of equipment can create a problem.

 

[Nemrod]

Yes-ish.

But this really does depend upon the dive conditions. Diving in poor visibility in a current on a wreck where there's a sporting chance the buddies get separated, diving with a reserve source of gas is an easy way to turn a life-threatening incident into an inconvenience and a great story back on the boat.

Hence in some locations it's very much the exception for someone to dive with a single tank only. In my early UK dives I literally held on to my buddy in really poor conditions to avoid separation. Didn't dive a single for long; moved to a twinset as soon as I could (and could do the shutdowns).

LOL, again you mention specific circumstances and I made a generalization which I also stated that generalizations fall apart when specifics come to bear. You have specific needs due to circumstance that you describe. Then you need to adapt and I would not disagree with alternative solutions such as yours.

James

 

[boulderjohn]

As I understood his argument, Hartattack said that redundancy was not necessary as long as you watched your gas carefully and always began your ascent with enough gas to ensure that you and another dive sharing air could ascend using the GUE ascent profile. He said (incorrectly as I understand it) that such a profile would require two divers to take 9 minutes from 80 feet.

Well, I think he has a point. If you always cut your dive time in order to begin your ascent with an enormous amount of usable gas, the odds of your needing a pony are pretty slim.

I pointed out that regardless of how much gas was in the cylinder it was not much use if it became unavailable.

The irony in my statement was too subtle. Sorry. Let me explain.

Hartattack's argument assumes that the diver will be so vigilant in monitoring gas supplies and so conservative in reserve planning that will be impossible for the diver to run out of gas. He also assumes that catastrophic gas loss cannot happen. Many people would prefer not to make those assumptions and therefore carry a pony.

I will repeat my own preferences made earlier in the thread.

• I do feel confident enough in my own gas planning and monitoring that I am sure I will not run out of gas during an NDL dive, but I will not give up pleasurable dive time to leave that much in reserve when a much lower reserve will suffice nicely.
• Catastrophic gas loss (sudden and complete loss of gas) is incredibly rare. If one were to occur, I feel confident that on almost all dives, I could deal with it easily.
• Consequently, I do not carry a pony except for occasions when I am in situations where I am more on the edge of technical diving, meaning that easy access to the air on the surface is potentially compromised.
• If I am planning a technical dive, I follow technical procedures and always have redundant gas.

 

[boulderjohn]

It occurs to me that a problem may be that some people firmly believe that the same rules and procedures need to apply to all diving, while others prefer to believe that different dives can be treated differently.

I first had this thought while muck diving a house reef in the Philippines. On many dives, I was never more than 25-30 feet deep, a few sloping feet from shore, diving with an AL 80. There was no real potential for DCS. I was going to get bored with the dive and surface before running out of air, and if I did run out of air somehow, it was an easy CESA to the surface. I could do those dives safely with no computer, no SPG, no depth gauge, no alternate air source. The only reason for even a watch would be so I could log the dive or know when it was time to go to lunch.

As dives get deeper and more complicated, the need for more equipment grows. Some divers prefer to make decisions as to what is needed on those dives. Others believe equipment should be standardized, with the same gear for all dives.

 

[scubaozy]

The incorrect use of any piece of equipment can create a problem.

Yes it can. I am pretty sure those folks taking ponies with them belived that they increased their safety and they did know how to use the equipment.

My normal buddy is cheap and does not maintain his gear at all. He simply buys whatever cheap gear he can find a "deal" on.

Lets hope he is not paying for an internet subscription and reading this.