Pony Regulator

[buddhasummer]

Good eye, it's actually a G260.

Thought for a minute perhaps SP had come out with a new model while I was sleeping.

 

[loosenit2]

1. Additional stage is added in case the 100cf is needed by both divers. I've struggled with if it's actually needed with the 40cf being available.

2. If I'm at 115ft the 19cf will be used up too quickly though would probably be enough to surface quickly. The 40cf gives me enough time to be confortable if an issue comes up.

2a. Just regular buddy recreation diving with no penetration and within NDL. I'm also in MI so low visibility and 40 degree water is common.

I never used a 19cf until about my 130th dive (this year) and find the comfort level I get with having it (and the extra air when needed) is worth it. I honestly cannot tell the difference of it mounted or not.

Thank you

I agree with @Marie13, the value of standardizing your setup far outweighs any perceived benefit of switching your gear to achieve “optimal” configurations, muscle memory is a powerful thing.

You said you are doing pure recreational diving with a buddy. Under those circumstances it is unusual, but not unheard of, to use a pony bottle. I personally use a 19 cuft back mounted pony, but only when I solo and the independent air source is needed.

Generally when using a pony in this configuration you have one one first stage and one 2nd stage on each bottle, having a third 2nd is messy for routing and gear configuration and could lead to confusion when you least need it.

On pony bottle size do what you are comfortable with and is supported by your gas planning. I have a SAC of about .5 cuft/min. So an ascent from 130 ft at a leisurely 33 ft min rate would look like:

130 - 99- 4ata- 1 min - 2 cuft gas consumed
99 -66 - 3ata - 1 min - 1.5 cuft gas consumed
66-33- 2ata - 1 min - 1 cuft gas consumed
33-15-1ata - 30 sec - .25 cu ft gas consumed
15 ft safety stop 8 min - 4 cuft gas consumed
15 ft to surface - 30 seconds - .25 cuft consumed
Total time 12 minutes, 9 cuft gas consumed.

Thus I have concluded a 19 cuft pony supports my needs with plenty to spare, but your calculations may vary based on assumed consumption and safety margins you desire.

 

[tbone1004]

Current setup...
Above 60 feet: 100cf primary with one xtx50 reg and one 19cf back mounted with a mk15 1st and g260 2nd
Below 60 feet: 100cf primary with TWO xtx50 reg and one 40cf front mounted with a mk15 1st and g260 2nd

I like the current two configs though I dislike having to screw in the second XTX50 into the 100cf 1st stage when changing depths. I figure if I'm above 60' me and my buddy can surface safely on the 19 and 100. Having that 3rd 2nd stage though above 60 seems overkill or confusing as its not on the tank itself and instead my bc. Below 60 that isnt an issue and the reg for the pony is on the tank itself.

Possible solutions and questions...
- If I didnt own the i3 inflator I'd likely just buy and airsource and solve the issue that way. Buying a different BC and an airsource might be a solution though my preference would be an actual octupus.
- Would a LP "in-line" hose quick disconnect be a solution here? I could run a 6" LP hose to a QD then another hose to the regulator. This would allow a quick change out. Where could I buy this from please?
- What would you do where the 19 must be kept?

Thank you

Disclaimer, I don't believe in pony bottles, I think they're pointless, but if you're going to do it, then here is how you should do it.


you need to standardize and stick to it. If you like it back mounted, use the 40 back mounted, if you like it slung, then sling it.

Look at real redundant regulator setups with doubles and singles. 2x first stages, 2x second stages. No setup changes, no extra second stages, no quick disconnects, etc. KISS.
Your comment about the third second stage being confusing is correct, but why add the confusion when you're deeper and things get worse faster?
Here's my recommendation.

Ditch the I3, that's an extra second stage that you don't need. Will cost $20 to go to a normal inflator and be done with it.
Your 100cf tank will have a SPG, inflator hose *now the hose to your I3*, and the donatable second stage on it. That's it. Sounds like that is the XTX50. When you donate gas, you donate whatever you have left in your primary tank, which should always be more than is needed to get up.
Your pony bottle will have a button gauge, MAYBE an inflator hose if you're diving dry, and a second stage on it. This goes in a necklace under your neck for you to use.

The extra second stage is pointless and IMO downright dangerous in a real OOA scenario if you are budgeting on that pony bottle for one of the divers to get to the surface in a gas sharing scenario. With both of you on the same tank, if it doesn't have enough to get to the surface for both of you and you switch to the pony too late, the other guy is going to run out of gas and now you're buddy breathing. That's insane, don't make this complicated.

Ditch the 19. If you need a pony, the 40 is no more work than the 19, so commit to one setup and be done with it. The 19 could be used for drysuit inflation, or as a tank to check regulators, use for cleaning, etc. but you should never have both bottles on the same dive, and you should never have more than one second stage attached to each tank if you are going to use a pony bottle for bailout.

 

[Scubasteve1984]

Thank you for all of your feedback so far. Definitely helps concrete my thoughts and ditection. It is appreciated.