19 or 30 cubic feet?

[dave4868]

As for on a deeper dive and running the primary a little lower cause you have a pony is IMHO poor gas management.

I've heard that before, but it was never explained. I can see that planning on using the air in the pony may not be optimal, but it's not necessarily always "poor gas management", is it?

Is it always considered "poor gas management" because one can't be sure the pony will function when needed?

If one doesn't have a deco obligation or other ceiling, and worst case scenario for a failed pony is a surface swim, does planning on using the pony still constitute "poor gas management"?

Dave C

 

[ReefHound]

The pony is an emergency air supply, is it proper gas management to plan on having an emergency?

 

[Ironman]

What do you guys think of 30cft ponies? Do they get used for deco by tech divers at all?

30s are used, perhaps not as frequently as 40s. I dive 30s as deco bottles when the required gas supply, with reserves, allows me to use the 30, instead of a 40 (or an 80).

I tried to hold a 19 vs a 30 yesterday to simulate a sling, I think the 19 would deff be more comfortable, but the price thing makes me want to go bigger.

In the water, it is less likely you will notice a difference in a slung 19 vs a slung 30 or 40.

As for on a deeper dive and running the primary a little lower cause you have a pony is IMHO poor gas management.

If the dive planning is done in an intelligent manner, with budget for appropriate reserves, there is little wrong with using the pony as a supplemental back gas supply. Personally, when I do that, I prefer to go to my pony supply mid-way through the dive, rather than running my primary backgas low, and switching to the pony. If I have a problem with the pony – reg, tank, whatever, - and I find out mid-way through the dive, I go to my backgas, turn the dive as appropriate and surface with adequate reserve.

 

[dumpsterDiver]

..... Personally, when I do that, I prefer to go to my pony supply mid-way through the dive, rather than running my primary backgas low, and switching to the pony. If I have a problem with the pony – reg, tank, whatever, - and I find out mid-way through the dive, I go to my backgas, turn the dive as appropriate and surface with adequate reserve.

I do the same thing with a 13 cu-ft pony. I have no guage on my pony so I can not tell if it really has any air in it at depth. So if I am going to be an idiot and push the limits, I at least try to be smart about it.

Did it a few weeks ago when I was down low on air at 115 feet solo and another fish came in that I just had to spear. Switched to the pony and saved 500 psi in the primary tank as back-up. At least I am reasonably sure the main tank will have air if I really need it.

I do this stupid stunt VERY infrequently (maybe once every 2-3 years), but it could be an important technique in a true emergency. Possibly in a situation where a diver is struggling to free an entangled buddy and is getting low on air in the primary tank for example. He might decide to save his primary gas and that he will work on his buddy's problem until his own pony runs dry and then at that point he might decide to rip the guy out of his scuba gear or even abandone him.

Not a good situation but it makes sense to me if you choose to dive a back mounted pony with no underwater pressure guage (as I do).

 

[Scared Silly]

If the dive planning is done in an intelligent manner, with budget for appropriate reserves, there is little wrong with using the pony as a supplemental back gas supply.

At this point you are using your pony bottle as a stage bottle which is different as you have now planned for that gas. The general usage and definition of a pony bottle is for emergencies.

I do this stupid stunt VERY infrequently ...

As a friend says "we all do dumb things, most of the time we get a way with it, sometimes though we do not"