Pony practice...what do you do??

[Tanked]

Why do i keep getting sucked back into these arguments?

 

[drdaddy]

I did a while back. It has a lot going for it, probably the only way to work with a large pony. Compact, easy to access, balances fine.

I just could not get past having a big metal tank in front of me. I like to get in close and look at tiny critters on the reef and/or take pictures in macro without damaging the reef. If my style of diving was different or I was not so much of a klutz, I would reconsider.

I hunt and grab crab off the bottom on a regular basis. Any tank on a sling will drag on the sea floor and be in my way. My 19 cf pony is mounted on my tank with a (readable gauge on a hose that I can read - no surprises) and is turned on (I can reach the knob).

By the way, I don't plan on using my pony, but once I made a stupid/foolish rash call and went after that "one more crab" - a big one hanging on the wall as I was ascending. By the time I got to the surface (carrying 20+lbs of crab) the tide had turned and the mouth of the bay was rough and I was out of air, and ... Well I'm alive, thank God for the recreational crab boat.

Plan your dive and dive your plan - discipline yourself!

 

[drbill]

On very rare occasions the valve stick can get clogged. In that situation, a pony is nice to have. Separate first stages off of the same stick won't help.

I had one of those rare experiences on a day I hadn't strapped my pony back on my main tank. It resulted in a CESA from nearly 80 ft.

You are absolutely correct that a valve which has a single air pathway from the cylinder will fail to provide air. Hopefully my memory is correct that an H-valve has a single pathway, but Y-valves have dual pathways. If I am not right, I'd appreciate someone correcting this.

Of course ever since that incident I always strap my pony back on for a dive whether the plan is to go to 15 ft or 200 ft.

 

[drbill]

I mount my pony on my main tank. Slinging it causes it to drag on the bottom and make me slightly unstable since I am often resting on the bottom filming. I keep it off because the reg purge button can get depressed while I'm on the bottom filming. Every so often I charge the pony reg, both to keep air in the hose and as practice for reaching behind to get to the valve. I mount my pony upside down so the valve is at the bottom where I can reach it far more easily than over my shoulder.

 

[acwest]

If your setup includes a total of 2 second stages, as opposed to 3 (I see no benefit in a rig with 3 seconds, but it's personal preference), then you simply MUST have half your total rock-bottom reserve in the pony. That means your usable gas in the main tank just went up by half your rock-bottom. If you don't use it then you are just ignoring perfectly usable gas on your back.

Sorry dude, i have to disagree.
A pony bottle is there for emergencys only. The only gas you should PLAN on using is the gas in you main tank.

I think you misunderstood what hudson was saying. By counting the gas in the pony against your rock-bottom reserve, you aren't planning on using it, except in an emergency. The key point of rock-bottom in planning is that you are planning for an emergency, and making conservative estimates of how much gas you will require in an emergency, should one occur. It seems perfectly reasonable to include the emergency gas in the pony in your planning of how much gas you will have available in an emergency.

 

[Reg Braithwaite]

If your setup includes a total of 2 second stages, as opposed to 3 (I see no benefit in a rig with 3 seconds, but it's personal preference), then you simply MUST have half your total rock-bottom reserve in the pony. That means your usable gas in the main tank just went up by half your rock-bottom.

My 2psi from the vantage point of my comfy and dry couch:

The third second stage definitely complicates things: You need to have rock bottom in your back gas AND half of rock bottom in your pony. If you only reserve half of your rock bottom in your back gas, you run the risk of going OOG twice in one dive without the benefit of a S----A--. This will happen if you and your buddy get on your back gas rather than handing the pony off. You'd have to switch to the pony and buddy-breathe off it!

With one first stage on your back gas and one on your pony, in the event of your own OOG you switch and thumb the dive, no problem. Half of rock bottom is enough air for one diver to resolve a problem and end the dive. If your buddy needs the gas, they get half rock bottom from one tank and you get half from the other, again no problem. And if there's no emergency, you turn the dive when you reach half of rock bottom and breathe that down from your back gas to end the dive.

So... With two first stages if you have half of rock bottom in your pony you can breathe your back gas down to half of rock bottom without relying on your pony for a non-emergency. Do I understand your reasoning correctly?

 

[hudson]

And if there's no emergency, you turn the dive when you reach half of rock bottom and breathe that down from your back gas to end the dive.

I know that's what you meant but to be more accurate, start your ascent when you hit half your rock-bottom, as you should probably turn it much earlier unless you are drift-diving or going straight down and back up

So... With two first stages if you have half of rock bottom in your pony you can breathe your back gas down to half of rock bottom without relying on your pony for a non-emergency. Do I understand your reasoning correctly?

Exactly. This extension of usable gas even though you don't breathe the pony is not really a reason to carry one, but it's a nice side-effect regardless, compensating for the additional drag caused by the pony.

 

[wedivebc]

Sorry dude, i have to disagree.
A pony bottle is there for emergencys only. The only gas you should PLAN on using is the gas in you main tank.

Whether you agree or not carrying extra gas in addition to the back gas and being included in the plan is a very common practice. There are plenty of cave and tech divers doing it every day. So can it only be used for emergency when its called a pony? Let's call it a stage bottle then.

 

[Tanked]

Whether you agree or not carrying extra gas in addition to the back gas and being included in the plan is a very common practice. There are plenty of cave and tech divers doing it every day. So can it only be used for emergency when its called a pony? Let's call it a stage bottle then.

I guess it all comes down to wording. I don't concider a pony bottle the same thing as a stage bottle.
The 30cf tank i have strapped to my main tank doesn't come into play when I plan a dive. I know its there if an emergency should arise, but thats the only time I plan on using it

 

[wedivebc]

I guess it all comes down to wording. I don't concider a pony bottle the same thing as a stage bottle.
The 30cf tank i have strapped to my main tank doesn't come into play when I plan a dive. I know its there if an emergency should arise, but thats the only time I plan on using it

There is nothing wrong with you doing it that way but you said:

The only gas you should PLAN on using is the gas in you main tank.

Which implies it is wrong for anyone to do it and I disagree with that.