Considering buying a pony/back-up tank.

[mi000ke]

There have been several similar threads over the past few months that address your questions, and they all generally motivate the same debate and set of issues/arguments around size, safety, use, nomenclature, mounting, etc. So worth doing a search.

I sling a pony on dives greater than 50' for peace of mind, as the cost and effort are minimal, and despite some who argue to the contrary, when you are trying to breath underwater, more air is better than less, IMHO. (And as I joked in another thread, if you think that having more air is a potential safety hazard, then reductio ad absurdum, you should only freedive).

If you are clear on why you want to carry redundant air (for me it is as a bail out in cases where I am not totally comfortable counting on someone else to save my bacon, and is never a part of my gas plan), then you can compute your needs rather than guess. I did the math - see the link below - (and by way of calibration, at my SAC rate of about 0.4 cf/min. I computed that I needed 13 cf to ascend from 100' including time to recognize the problem and settle down for a minute or so, doing a controlled ascent, a safety stop, and doubling my SAC to account for stress).

Pony bottle

 

[Marie13]

I nearly broke SB by starting a 64 page thread on ponies back a few months back. My absolute favorite comment:

On just a regular recreational dive in the Caribbean vacation, I would not even get on the boat if someone was going to use a pony bottle. Just a sign that I am about to dive with an incompetent. Sorry.

Do you actually see people diving with pony bottles?

 

[Bierstadt]

Be the thinking diver rather than one who wants to buy equipment to make a dive "safer".

Now that is one statement I can wholeheartedly agree with. Gear is not a substitute for skill, but rather a tool. Tools can get one into or out of trouble depending on how they are used and how they affect the user's thinking.

That being said, I am a Great Lakes diver and the rule of thumb in my area is to carry a pony on any dive beyond what the diver can do a CESA from, generally about 60 feet. I feel that relying on one's buddy is dependent on the buddy skills and diving habits of the buddy in question. I have one buddy I have dove with that I was fully comfortable in his reliability if I had a freeflow or whatever it might be to deprive me of my gas. The rest of my dives, not so much. I can keep track of my buddy till the cows come home, but when it happens that I am always the one initiating communication and checks and whatnought I am not exactly filled with confidence. I imagine that those divers fortunate enough to have a 100% reliable regular buddy will feel less need to have a backup air supply than the rest of us.

As for me, I plan on going tech and so my pony (which I am still assembling) is an al40 with the same Deep6 regs as my main tank and a stage bottle rigging. The norm in my area for recreational divers is an al30 and dedicated pony regs (not sure what they are but my LDS sells them and they appear purpose-made for ponies, single lp hose, integrated spg, etc).

I think that a diver that bolts to the surface at the first sign of an air issue with a pony is not going to be much safer without one. Either way that diver is an accident waiting to happen, and no amount of gear is ever going to fix the actual problem in question.

 

[Bierstadt]

I nearly broke SB by starting a 64 page thread on ponies back a few months back. My absolute favorite comment:

On just a regular recreational dive in the Caribbean vacation, I would not even get on the boat if someone was going to use a pony bottle. Just a sign that I am about to dive with an incompetent. Sorry.

Do you actually see people diving with pony bottles?

Mine too.

 

[KevinNM]

Well, it does tend to keep the boats I dive from free from irrational divers. I just wish I could get everyone driving a car to run home if they see a pickup on the road.

 

[MichaelMc]

I got an LP27 with modular valve. Big enough to let me solve most problems with time to spare. Short enough, at 14”, to be easier to fly with. Empty, its neutral weight is 2.5 pounds heavier on land than a 19, and it is 3 pounds more negative than the 40. But I can fix the extra negative on my left with weight distribution.

Rigged with side mount loop bungee on the left side of my BP/W. So, like a stage, but more streamlined. Though that does put the valve out of view normally.

For me, it’s a significant and travel capable pony, for solo or random buddies, and a baby step toward learning side mount rigging. Sort of a short and light stand in for an LP50. But…, I have not dove since I got it. For local use it might wind up a victim of trying to fill too many roles at once.

 

[MichaelMc]

(replied to self, Oops)

 

[Bert van den Berg]

I nearly broke SB by starting a 64 page thread on ponies back a few months back. My absolute favorite comment:

On just a regular recreational dive in the Caribbean vacation, I would not even get on the boat if someone was going to use a pony bottle. Just a sign that I am about to dive with an incompetent. Sorry.

Do you actually see people diving with pony bottles?

The dive boats in New Zealand require you to have a redundant source of air if you dive solo. Although I don't know you it's sad that we will never meet because you would consider me to be incompetent for taking the required pony bottle and would not get on the same boat with me?

Perhaps there are circumstances where you might make an exception.

 

[Marie13]

The dive boats in New Zealand require you to have a redundant source of air if you dive solo. Although I don't know you it's sad that we will never meet because you would consider me to be incompetent for taking the required pony bottle and would not get on the same boat with me?

Perhaps there are circumstances where you might make an exception.

Bert, I was quoting someone else (my favorite comment from the other pony thread). I sling a 30cft pony myself regularly.

 

[Bert van den Berg]

Bert, I was quoting someone else (my favorite comment from the other pony thread). I sling a 30cft pony myself regularly.

Hi Marie,

Thanks for clearing that up!

Maybe we CAN dive together sometime.

Regards

Bert