How many non-tech divers carry a pony bottle?

[Meng_Tze]

I think you might be missing the point. "Extra gas" is a great idea. Redundancy is also a great idea. Extra gas and redundancy in the form of the, usually very small, tanks divers use as pony bottles, don't even come close to solving some of the problems that inspire divers to use them in the first place.

Some examples... the very nature of a pony bottle, stage or decompression cylinder (no redundancy, the way they are carried ect) make them more prone to damage or loss than back gas. So...they make a poor backup.

From a gas planning stand point, our reserve gas needs to be sufficient to get us and a buddy to the surface. When I dive stages, I breath the stage gas first and keep my reserve gas on my back where I have some redundancy. On some dives we even dive only using the stage gas and reserve ALL of our back gas.

The way they are configured can also cause problems. A third reg pinned to your body is a configuration night mare and more than one diver has died because they grabbed the wrong one and breathed their pony empty not realizing what was going on.

Divers often carry them such that the valves aren't accessibly. If the valve is on and you can't get to the valve and the reg isn't in your mouth it's more prone to free flows or other loss. What about the SPG? Can you see that?

If it's carried with the reg/hose stowed and the valve off, it's not a very readily deployable emergency source is it? Still, that's how we carry stage and decompression tanks in an effort to NOT lose that gas.

If a pony is symbolic of anything, it's usually that the diver has started doing dives that is pushing it for the training and equipment that they have. Once they get a little more of both, they usually realize that they don't need pony bottles.

The OP asked about non-tech divers using pony bottles. As others have pointed out, it's usually non-tech divers who do use them. It's also non-tech divers who have less training in gas manegement and equipment configuration. From that perspective, I think you're right in that someone here doesn't know what they're talking about. I'm just not sure that you've correctly identified just who that is.

Couldn't have said it better myself Mike

 

[Jon C]

Well, my reason is a little different. I carry a small pony on my BP/W only when I solo dive. (You hardcore DIR'ers hold those cards and letters...PaaaaLEASE!)

Not for the extended bottom time, or for an emergency. Rather to avoid rehashing the "What if you run out of air?" argument with my non-diving wife. I tell her "Thats what the pony is for." It seems to give her peace of mind and avoiding the discussion is worth the added drag and gets me out of the house quicker.

And of course, should a great white come along, I can shove the pony in its mouth and shoot it, causing it to explode saving my life, the boat and, in somecases, a helicopter...as I have seen done somewhere before. That way, I have stopped the 25 foot maneater and still have my main tank to continue my otherwise routine dive.

Jon

 

[Jibeho]

Well, my reason is a little different. I carry a small pony on my BP/W only when I solo dive. (You hardcore DIR'ers hold those cards and letters...PaaaaLEASE!)

Not for the extended bottom time, or for an emergency. Rather to avoid rehashing the "What if you run out of air?" argument with my non-diving wife. I tell her "Thats what the pony is for." It seems to give her peace of mind and avoiding the discussion is worth the added drag and gets me out of the house quicker.

And of course, should a great white come along, I can shove the pony in its mouth and shoot it, causing it to explode saving my life, the boat and, in somecases, a helicopter...as I have seen done somewhere before. That way, I have stopped the 25 foot maneater and still have my main tank to continue my otherwise routine dive.

Jon

That is the best reason I have read in this thread which mostly full of HOT AIR and Chest Pounding!

 

[Diver0001]

Did you even read my post? Maybe I didn't use 1000 words to answer, but the answer is sure there.

Sorry. That didn't come off like I wanted it too. Too many frustrations just under the surface these days. I wasn't really responding to your post as much as using it for a soap-box.

R..

 

[Jason B]

Sorry. That didn't come off like I wanted it too. Too many frustrations just under the surface these days. I wasn't really responding to your post as much as using it for a soap-box.

R..

No sweat.

 

[KMD]

The rule of thirds assumes that you will use the same amount of gas on the way back but...that's a factor of sac/RMV and swimming speed.

We apply the rule of thirds when we MUST get back to the starting point. If that is the case, that rule of thirds is applied to a gas supply that has redundancy...manifolded doubles, independant double or even a single with an H-valve. If there is something about the open water environment that causes you to think that you need to treat it like an overhead, then you should treat it like an overhead...and a pony doesn't cut it.

If we MUST make it back then the rule of thirds is the most liberal gas plan that we use. For example, we might turn on thirds in a spring (flowing out) that we are familiar with. Since we have the flow pushing us out we get out much faster, with much less work and using much less gas. In low flow or no flow conditions or where there's is anything else that may complicate the dive we turn before a third of our supply is used.

If your RB is 1500 psi and you use 1000 outbound you are obviously not planning on getting back under water. Rock Bottom is ascent gas. What's left is useable. How you manage the useable portion is what determines whether or not you are going to get back to the starting point. Even using the rule of thirds, "thirds" are calculated after ascent gas or RB is backed out.

And that was my original point. Just doing thirds is not always the most conservative nor the appropriate strategy. The majority of its use and application applies to more technical dives (of which I include overhead environment)

 

[Meng_Tze]

And that was my original point. Just doing thirds is not always the most conservative nor the appropriate strategy. The majority of its use and application applies to more technical dives (of which I include overhead environment)

Just out of curiosity, what do you propose then in circumstances you feel rule of 1/3 is not the most conservative, or inappropriate strategy. Can you give an example, a situation where it would be inappropriate? Unless you go super conservative (like for instance 1/6th or 1/8th) 1/3rd would be very conservative in OW?

BTW Overhead does not always mean a physical overhead... it can be deco ceilings, having to go back to the point of entry (i.e. going back to the anchor line, not always a tech dive)..

 

[vanDavid]

Being a buddy is a two-way street, having a pony won't change my current behaviour regarding buddy proximity.

I think that most divers who maintain poor buddy contact are going to do that regardless of gear or configuration.

Potential negative: You won't feel the need to stay as close to your buddy, or watch them as much.

Just a thought

 

[marusso]

3000 PSI in tank. You decide to have 1500 in RB: 3000-1500 = 1500 usable.
1/3 of 1500= 500.

So you go in and use 500 psi gas untill the spg shows 3000-500=2500
you turn the dive at 2500. If at this point you have a total OOG and both divers NEED to go back to the point of entry, you have ample gas left. 500 for you, 500 for buddy equals 1000. This example is based on your numbers above, on how I would do it, but make sure YOU understand what this means to you and do not copy blindly.

And on top of that:
2500-1000= 1500 in 'extra reserve'. How much you need/want in reserve is a personal choice.

That is what I was implying. Just saying using the rule of thirds can be misleading. One may presume that that implies using 1,000psi out, and 1,000 psi back.

Whereas in your example above is the proper procedure taking into account elevated SAC rates due to stress, and time to make a proper safe ascent.

As you properly stated, it is a third of available and usable gas, not reserve gas.

-Michael

 

[Web Monkey]

If it's carried with the reg/hose stowed and the valve off, it's not a very readily deployable emergency source is it? Still, that's how we carry stage and decompression tanks in an effort to NOT lose that gas.

Sure it is.

It takes like 4 seconds to rip the second stage out of the bungee loop that holds it, and turn the valve on.

Terry