Pony bottles

[17-40]

I'm wondering what size pony does everyone use and what is the smallest suggested or allowable by standards. The deepest water we will be in on a call is 20' tops but we do go to some of the local quarrey's to practice and train which are around 40' max. We may go to one spot a year that is deeper than that but not very often.

 

[tc]

We use the 19 CF. Nearly the same weight and buoyancy characteristics as the 13, just a couple of inches longer. Almost half again as much air with only a minimal additional weight.

For deeper work we use 30 CF.

I know ERDI is minimum 18 CF, not sure on the others.

 

[off the grid]

I use the 19 cf as well. Used to have a 13 but the 19 supplies a good percentage more air with any noticable difference from diving with the 13.

 

[bridgediver]

19cuft should serve you well.

This has been asked allot on here. I'm not familiar with anyone using something else on here for the depths you list

 

[Yotsie]

We run a 30 cuft pony.

 

[NudeDiver]

I too am looking at getting a pony setup - not for tec stuff per se, but just as a redundant air supply in case of reg free flow (cold water), potentially ice diving, or to hand off to a buddy who needs air. Should also be suitable for solo diving safety, when I get to that point. Because I want to be able to travel with it, I was thinking a 13 for my needs - considering its smaller size. Is a 19 really that much better or necessary?

 

[tc]

Here's a link to the Catalina cylinders page-

SCUBA Cylinders

Bottom line- 19 is 2.1 pounds heavier and 4.7 inches longer than the 13. Diameter is the same.

Filled buoyancy is only 2/10s of a pound different and empty is 6/10s of a pound, no really meaningful difference.

The 19 is about a 45% increase in capacity over the 13.

The best way to answer your question is to figure out your air consumption (Preferably under stress) and look at the depths you will be diving and then figure out how much air you could need to extricate yourself from the problem or situation that caused you to run out of air, make an ascent at a safe speed and hopefully even toss in a safety stop.

And then toss all of that out the window when you figure out that if you have to donate it to someone else you have no idea what their air consumption is but that they will likely be pretty agitated by having run out of air and the bottom line is really that the more air you have the better!

For me the added length is not important- the two biggest changes between the cylinders is a 2.1 pound increase in the dry weight in order to get a 45% increase in capacity, I've always felt that 2 extra pounds was probably worth the extra margin of safety.

Good luck with your decision!

 

[dittrimd]

Great post TC I did not realize the differences between 13 vs. 19.

We use 13's because our deepest lake is 60' and we are never more than 150' from the hole and there is always a safety diver with an AL80 contingency bottle so the 13's work for us.

I agree that there is no hard and fast rule about size just that you need a completely redundant source. As with most things you need to look at what works for you and your team.

I always like to throw in a vote for the quick draw pony bracket. Take a look it works great.

Mark D.

 

[17-40]

Thanks for all the information I will take it back to the others to see what they want to go with the 13 will work for us probibly due to or deepest depth is only 20' or so in the lake we cover but the 19 sounds even better for when we go rec. diving but even then we don't go much deeper that 50'.

 

[caver]

I'm wondering what size pony does everyone use and what is the smallest suggested or allowable by standards. The deepest water we will be in on a call is 20' tops but we do go to some of the local quarrey's to practice and train which are around 40' max. We may go to one spot a year that is deeper than that but not very often.

My question is this, due to the shallow limits of PSD and the fact that each diver is in the water no more than 20 minutes max. Why would you need a pony bottle?