Couple questions on a pony bottle for bail out

[kwinter]

Good points, but you're overlooking the hassle of trying to get a PP Nitrox fill when you travel with a pony.

We weren't talking about travel. I specifically stated that after air travel with the valve off, it would clearly be an air fill. But actually I would siphon off from a nitrox tank if I could. Depending on where you travel, O2 clean might mean nothing. Or nitrox could be banked or continuous blend or membrane system.

Somebody might find themsleves deeper on a wall than they want... I would rather have air.

Just keep talking out of both sides of your arse. Now you're diving by accident because you're deeper on this wall than what you planned. I'm curious what gas is in your main tank for this dive. Unless it is air, don't give me this crap that "I would rather have air." If you have nitrox in your primary tank, you are in just as much danger if you end up deeper than you wanted to be. More danger, actually, unless you requested something leaner than the 28% that should be in your pony.

How can you extol the benefits of diving nitrox in your primary tank and not realize it is clearly better and possibly even more important in your emergency supply? Set the cost and availability aside and decide what gas is best. Then realize that it is a one shot deal. A 6 or 13 cf tank might need topping every 10-20 dives. A 19-30 cf pony should last at least a year. And it doesn't need to be dumped to be topped at a decent shop.

Or just continue to be not only cheap, but irrational and stupidly argumentative. I'm amazed that after 40 years I can still get so irritated at such a small mind.


iPhone. iTypo. iApologize.

 

[maniago]

I'm amazed that after 40 years I can still get so irritated at such a small mind.

Oh well let me explain it to you: South Jersey.

 

[markmud]

You are all missing the point. The supposition is that we are talking about a recreational nitrox diver. No deco. Nothing deeper than 40m/132 ft. There is no diving you are going to do that you can't use 32% (at 1.6 max) or 28% (at 1.4 max). You pay for the pony fill one time. The bottle remains full unless needed for an emergency. Yes, a tank of air might get you to the surface. But why put yourself into a situation that is clearly sub-optimal? Let's examine the reasons you list for using air.



A single nitrox 28% or 32% fill on a pony bottle would be less than a couple of beers and last at least a year unless used. And if you don't think nitrox is SAFE, you shouldn't be using it, EVER!



Use an analyzer, like you were taught. Or demand a refund from your nitrox course.



As long as you stay within recreational limits, the one fill of either 28% (max pO2 1.4) or 32% (max pO2 1.6) will be breathable at any depth. No need to ever dump and refill.



WTF? You're worried about an OxTox hit at recreational depths within NDL for a max of 32%? Please ask for that refund ASAP. AFAIK there has never been a documented case of OxTox under those circumstances.



Then you should be diving air in your primary tank as well. There is absolutely no justification for saying nitrox is better in your main tank, but air is better in the pony. Even if you don't push close to NDL, you would finish the dive on nitrox if you didn't have whatever equipment problem caused you to go to your pony. But once you have that issue and grab the pony reg, you would rather be breathing a different gas? Preposterous.



Then why would you have 36% in the pony, EVER? C'mon folks, use some logic and rational thought.



Just how complete a jack_$$ you are remains to be seen, since you are blindly agreeing with people whose arguments are nonsense.



Once again, it is a one-time fill. You don't match anything for every dive. Once it is filled, it stays filled unless you need it or have a reg free flow, etc. It is there for you every dive. There is nothing wrong with having a pony with 28% even though you have air in your main tank because you are only diving to 20 feet today. But having the richest gas you can use at the max depth you can dive is always at least as good as air and usually better.

FYI, rebreather divers take bailout tanks with them in case of a problem. They are nothing but big (minimum 40 cf) pony bottles. They don't get used unless there actually is a problem. I probably top mine off every couple of years. We don't dump the gas and refill them with the "ideal" gas for the dive we are doing. We have several tanks with different mixes and take whatever we need without exceeding the MOD. Since a recreational diver with a pony would only have one emergency tank, it should be the richest gas that can be used at the maximum depth you are going to dive. If (by the book) you limit your diving to 40 meters/132 feet and you only feel safe with a max pO2 of 1.4, then fill your pony with 28% and be done with it. Maybe it will cost you $10. It will last until you have to pull the valve for your next flight.

I don't know how to explain it any clearer.

Hey Kwinter,

You explained yourself very well and your opinion is crystal clear.

However, using nitrox does not fit my goal and strategy. If I am at 120 fsw and my primary suffers a catastrophic failure, I will strive to perform a 2 1/2 minute pony bottle ascent. In 2 1/2 minutes, I won't load enough nitrogen to create a critical situation.

I don't do overheads, I don't do deco, I don't dive deep, and I am not a techie. Also, I am a "fairwater" diver.

Some have opined that recreational divers don't use pony bottles for safety reasons. I tend to agree. A CESA is a viable option for most rec dives. The poster that I am thinking of wrote that using a pony rig makes some rec divers feel comfortable. For me, he is correct. I use my 6 cf bottle when diving with competent buddies because I don't want to hold my breath while searching for my buddy's octo, if my primary suffers a catastrophic failure. And, I don't want to communicate with a buddy if I need to surface, other than to let him know that the dive has been "thumbed."

I have figured out that many on this board think I am cracked and they probably would never dive with me. You may be one of them. That's OK. I will just have to dive solo again.

markm

PS: I solo with my 13cf pony rig.

 

[dumpsterDiver]

We weren't talking about travel. I specifically stated that after air travel with the valve off, it would clearly be an air fill. But actually I would siphon off from a nitrox tank if I could. Depending on where you travel, O2 clean might mean nothing. Or nitrox could be banked or continuous blend or membrane system.



Just keep talking out of both sides of your arse. Now you're diving by accident because you're deeper on this wall than what you planned. I'm curious what gas is in your main tank for this dive. Unless it is air, don't give me this crap that "I would rather have air." If you have nitrox in your primary tank, you are in just as much danger if you end up deeper than you wanted to be. More danger, actually, unless you requested something leaner than the 28% that should be in your pony.

How can you extol the benefits of diving nitrox in your primary tank and not realize it is clearly better and possibly even more important in your emergency supply? Set the cost and availability aside and decide what gas is best. Then realize that it is a one shot deal. A 6 or 13 cf tank might need topping every 10-20 dives. A 19-30 cf pony should last at least a year. And it doesn't need to be dumped to be topped at a decent shop.

Or just continue to be not only cheap, but irrational and stupidly argumentative. I'm amazed that after 40 years I can still get so irritated at such a small mind.


iPhone. iTypo. iApologize.

You have trouble discussing this without attacking someone. I explained my reasoning... I prefer air for a variety of reasons. You indicate that you want the richest mix that is practical for the depth.

Ive been using a pony for maybe 25 years now. I fill it with air at the dive shop and will whip it to full on the boat off the leanest tank i have available. Air is cheaper, easier and runs no risk of oxygen toxicity. You feel that a rich nitrox is safer because in the extremely unlikely event that the tank would be used, the reduced nitrogen exposure will be meaningful.

I find the argument of reduced nitrogen exposure unconvincing.

What is the probability that a recreational diver will be exactly at the no-deco limits when a failure occurs? Answer: LOW...

What mass of additional nitrogen will be absorbed during a direct ascent from 100 feet when using a 6 cu-ft (air) pony bottle (which you reference) versus a 28% bottle? Answer: Negligible

You also seem to fail to understand that nitrox will benefit a diver over the relatively looong bottom time, but the use of air during an ascent of 60 to 100 seconds (the time it takes to get shallow) will be miniscule. Your apparent inability to discern the considerable difference between these two scenarios is hard for me to reconcile.

Your argument that a 6 or 13 cu-ft bottle only needs to be topped of infrequently: The reality of the matter is that for small bottles, a 6 cu-ft bottle, in particular, it is important that it be filled completely, because you just don't have that much extra capacity in most situations. In addition, your argument for infrequent topping off is inconsistent with safe practice... the diver should check the reg before each dive and take a few breaths. Then on surface intervals the tank should be shut down to prevent loss of gas, but an hour later the regulator is often drained and needs to be re-pressuirized. Each of these cycles uses some gas. I often do 5 or 6 dives per day.

Do you actually use a 6 cu-ft bottle or or you just making it up as you go along?

 

[Jim Lapenta]

First of all for no deco diving having air or nitrox in a pony is not going to cause anyone to take a "hit". You are not doing deco dives. When you go to your pony the dive is over. As for keeping it full and filling once a year, don't bother buying one. Deploy it every dive outing so that deploying it becomes instinct. Otherwise it's dead weight you're just lugging around.

Sent from my SM-G900V using Tapatalk

 

[kwinter]

You keep giving reasons that nitrox isn't needed, not that air is better, other than the cost argument. And I use a 6 for suit inflation. It's too small for a pony. But a 13 is ok and I think the OP was deciding between a 19 or 30.

In summary - air is probably fine, but presents absolutely no advantage over nitrox. If nitrox is good for your primary supply, then it's best for your bailout as well.


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[JohnN]

We weren't talking about travel. I specifically stated that after air travel with the valve off, it would clearly be an air fill. But actually I would siphon off from a nitrox tank if I could. Depending on where you travel, O2 clean might mean nothing. Or nitrox could be banked or continuous blend or membrane system.

Very odd, your account must have been hacked, because earlier you said"

What justification could you possibly have for this? The only acceptable reason I can imagine would be the first dive after flying to a destination with the empty pony that could only be filled with air immediately after arrival. Otherwise this makes no sense whatsoever.

I suggest you get with site administration ASAP.

 

[lowviz]

Oh well let me explain it to you: South Jersey.

OK, I'm not in this. Too much on my plate right now.

But that is the most amusing post I think I've read in quite a while!

-Love and kisses, NORTH Jersey.

 

[kwinter]

Very odd, your account must have been hacked,

I don't see any contradiction. You fly someplace with the valve off and then need an immediate fill for a dive, an air fill is better than an empty pony bottle. I never said air was really bad, just not as good as nitrox. If you have the time or ability to fill it with nitrox from a banked system, CB system, membrane system, or transfilling from another nitrox tank, then that is better. And if you refused to do that because it would add $10 to the cost of your week-long Caribbean vacation, then I would be perfectly justified in calling you a cheap bastard.

See, now you're just trying to poke the bear. You'll end up on Santa's permanent naughty list. There is absolutely no way you can logically argue that nitrox is a better gas to have in your main tank while air is better in your bailout or pony.


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[uncfnp]

Gotta love the Jersey Boys!

Chris. I am in the scuba camp that believes that in most things scuba (and life), there is no one answer fits all situations. In this case, everyone is right (for their diving) and everyone is wrong (for others diving style). Just as in the tank size, read the responses and decide which is best for you.