Tank, Pony Second Stage set-up

[Captain Nimrod]

I dive solo in the Keys - typically 1 ATM or less.

Borrowing from Jersey wreck divers who believe (as I certainly do) that having two completely independant breathing systems is the way to go, but not wanting to go the typical deep/cold Jersey Wreck Divers set-up of twin tanks with independant stages or manifold with isolation valve, the following has been arranged and I invite comments.

Aluminum 80 and Aluminum 19 Pony clamped to eachother with first stages at equal heights. 19 Pony is to the right; a knife on the left front of BC (OMS w/Dive Rite bladder) and a 4# weight to the lower left of the AL-80 trim things just right.

Each tank has a first stage and it's own second. Black hose and reg for the AL-80 (Mares Abyss 05/MR22) and a yellow hose and reg for the Pony (Cressi Sub) which has the switch set to minimum which all but eliminates freeflow concerns yet can be breathed though not as easily as "maximum." The Cressi is clipped to the RF of the BC just to the right of my sternum where even if there was a freeflow the bubbles would be readily apparent, "in my face" so to speak.

After considerable discussions and pool drills, back-up second stage for the AL-80 was eliminated as 1) There would be no buddy to use it and; 2) my back-up was the yellow Cressi attached to the pony and; 3) one less chance for a freeflow and less stuff dangling around.

I'm going to use this set-up next week but had thought about mounting the pony inverted on the left side of the main tank and have the hose and reg coming from up/under my left arm. The thinking against such an arrangement was to keep air on right and everything else on the left.

I'll report back on how things worked when I return formt he Keys in a couple of weeks but certainly appreciate anything the brain-trust can share. Thanks in advance.

 

[waterpirate]

Hi Captain,
When i dive a pony i dive with the hose to second stage pressurised and the tank valve off. I have no octo on main tank, only primary reg. For me the accesability sp of the valve is the issue, can i reach it to operate.
If my pony is back mounted I prefer it upside down, valve reached easily with right hand, hoses routed under arm and to keeper on harness. I have a spg mounted to my pony bottle as well for gas management, an abort directly to surface is not allways the best option. The ability to manage the gas in pony bottle at several stops, and or do an extended safety stop is a valuble option in IMHO.
Eric

 

[Captain Nimrod]

Rather than having an additional SPG on a console or otherwise detached, I went witht he little button style guage that screws directly into the first stage HP outlet. It's good enough fo rme to check on the boat before a dive.

I appreciate your reply and see that I am not the only one to eliminate the octous on the main tank.

 

[DeepBound]

Aluminum 80 and Aluminum 19 Pony clamped to eachother with first stages at equal heights. 19 Pony is to the right; a knife on the left front of BC (OMS w/Dive Rite

Hi Captain,
Just curious, does the pony have an SPG, and if so, where do you clip it off?

 

[Captain Nimrod]

The pony has a PG screwed into a HP outlet right on its first stage. I'll check it on the surface but not during the dive as my thinking is that if I am on the pont bottle for any reason I am making a contolled ascent and the dive is aborted. I do not plan the pony. The pony only serves as a backup. Like I said, if I'm on the pony bottle, the dive is over and I'm on my way up.

For this purpose, I'm comfortable with the little PG on the pony's first stage even though I cannot see it furing the dive with my configuration. If the pony's second stage were to start freeflowing, I owuld easily see it as it is bungeed just under my face and slightly to the right - clipped to the right shoulder strap (upper) of my OMS-IQ.

 

[cold_H2O_diver]

I have a pony which I attach "sling style" to my right side D-rings (upper torso and weight pocket level). I believe Dive-Rite sells a sling rig of this type. Mine is home-built.

Like the Captain, I also use the button style gauge. Mine is mounted directly in the first stage. With the pony hung in this sling manner, I can look directly at the gauge at any time. It's at my right chest level. With the bottle in front of me I can access the valve and regulator easily. And, I can remove the pony if necessary.

The Captain's rig sounds well thought out, and is similar to those used by friends of mine. I like the front mount for its accessibility, however. Also, when buddy diving, I can take the pony off and hand it to another diver if need be - so it's handy there too.

I traded in my octo for the Atomic SS1 Safe Second that mounts to the low-pressure hose. So, I can move from solo to buddy diving without reconfiguring.

 

[hilti]

I've tried some different configurations, attached to the tank behind me, upside down behind my right arm, and the most comfortable set up for me is slung on my right side. I mounted it from the lowest chest D-ring at the top and from a yo yo behind my right shoulder. the upper connection is a strap that I can adjust out, and when I'm in the water I can push it away for a better view of something or just remove it altogether. I do also have a little SPG that screws directly into the first stage (I don't want to assume anything) and keep the second stage stored with two silicone bands against the pony itself. I do carry an octo and throughout the course of a dive switch regulators from time to time, probably every third dive I run on the pony for awhile just to stay familiar with everything. I just prefer to dive with a traditional set up and carry the pony for "bail out"~ It has worked the best for me so far

 

[DeepBound]

I dive solo in the Keys - typically 1 ATM or less.

How do you dive at less than 1 atmosphere? These must be very shallow dives at a high altitude?

 

[Captain Nimrod]

1 ATM zeroed for a sea level baseline.

Kinda like AGL versus AGL altitudes.

That said, there have been times when I've "hung at the bar" for a decompresison stop of at least and hour or more where the tiki bar was more or less at sea level and I was more or less diving at 1 ATM.

 

[redacted]

Unless you are also conserned with entrapment or surface hazzards, for shallow dives I'd leave my redundent gas supply about 30 ft up.