novice questions about emergency air

[MrMrEZG]

Next time you are at your LDS i want you to put your foot in your "instructor's" (and I use that term loosly) ASS!
The only thing that he taught you was to not trust him. Now, there is such a thing as "air depleation" exercises, were in the air is shut off, but the student and the instructor are aware of it happening. your "instructor" was wrong for shutting off your air without telling you about it first.

now to answer your ? a pony bottle is just like the tank on your back. it has a tank, a 1st stage and a 2nd stage. I dive a 13cft hanging under my right arm, but do not see a problem with it being on the left. I hope this is the answer that you were looking for.

 

[Duca]

Jack,

I'm new to diving too, but I've been very interested in picking up a pony bottle. Over the last month, I've gone through the same thought process you have.
I've just got to pick out the exact size and carrying configuration. I even bought a cheap reg set off of Ebay last week. Once I get it serviced and checked out, I'll buy my bottle.

 

[g2]

Originally posted by Lost Yooper
OK, just in case you get convinced you need a pony, I strongly suggest carrying it under your left arm and not on the back tank.

LY -- Please expand (no pun intended) on this: Why do you recommend mounting it under an arm rather than on the back?

(I'm wondering why a back mounted pony bottle would be a bad thing, but it's acceptable to use manifolded doubles -- also back mounted...)

Cheers,

g2

 

[britishdiver]

Hi all,

I would just like to voice a little concern about Spare Air, please do not relly on it to get you out of trouble a few breaths is just not enough in the panic of the moment!

If you are doing Rec scuba ie. no stops then a pony is a good starting point as it would get you out of most situations likely to be encountered.

If you intend progressing to more adventurous diving then I would go initially for a manifolded twin maybe 7 litres.

This is my choice for 0 - 30 metre dives, and gives me an excellent redundancy factor.

For years I was happy to dive with no redundant system because that was the norm, happiness through ignorance.



http://www.britishdiver.com

 

[Divemstr13]

I think the best pony size for those who do more challaging dives such as wreck penetration or anykind of overhead enviorment should be at least 19 Cu Ft. .Air Management is a given and Buddy diving has it's benifits but all to likely your buddy won't be there when you need him. What if your buddy got caught up in a ripping current in the Gulfstream during a wreck dive ? This happens more than anyone would care to admit. The school of thought on relying on a buddy is changing. Usally one diver is prepared ( self sufficent) and the other (usally of less expirience) is not prepared and has nothing to offer you in the way of help. You must prepare yourself to be totally self sustaining. H valves will not give you more air when you need it. You gear configuation will depend on the type of diving you do. Emcumberance is overcome by practice with a consistant gear configuration. Think of your dive as a spacewalk. If you could have an alternative air source in case of equipment failure would you ? If it only cost $70.00 more to have 3-10 times more Cu Ft of air with a pony of 6 cu ft or larger vs spare air, is that worth it to you ? One of my ponies is a 40. It has a 5' hose on the reg. most would say that set up is excessive, and for most diving it is. You would'nt if you where entrapped in and underwater obstruction.

 

[large_diver]

Mouting pony under arm -- "stage" style:

- You can access it
- You can see via pressure gauge how much gas is remaining
- You can hand it off to someone if need be
- You can take if off if entangled (assuming usage of bolt snaps)
- Can wait to mount it until just before you enter water
- You can take it off and hand it off on boat dives before exiting water
- Lower profile than back mount = less effort to move through the water

I'm sure there are others I've forgotten.

One note -- you want AL stages, since they are close to neutral when full.

Ultimately you need to understand the amount of gas you need to ascend from the depths you will be diving in choosing which redundant system is right for you.. Ideally, this would be at a 30 ft per minute ascent rate and include a safety stop for deeper dives. With spare airs, it is unlikely you will be able to ascend slowly and make the stop, especially if you are stressed and using air at higher than normal rates. Below is a link that provides "typical" air consumption rates for ascents from various depths...scroll down to see the chart. READ THE FOOTNOTES at the bottom of the chart to understand their assumptions in calculating these consumption rates.

http://scifi.squawk.com/scuba.html#PONY

 

[Rick Murchison]

For recreational diving to about 30M (100') I use standard gear - no pony. If I'm the instructor in charge of a group, I'll often, though not always, carry a 30CF pony - depends on who's in the group, where, etc. The pony is clipped for easy detachment and handoff. (I clip on the left)
About the only other time I carry a pony is when it's filled with deco gas.
Any overhead environment dictates an "H" valve or manifolded doubles - access to the entire main gas supply from two separate regulators, and at least one and preferably two buddies.
"Running low on air" is planned out of the dive prior to going feet wet.
Rick

 

[Lost Yooper]

G2, LD hit about every point. I would add that a back mounted pony is more likely to become entangled and banged around during the dive.

Another argument that is often made against the use of ponies for recreational dives is that many divers will begin to "rely" on the pony instead of relying on diving skill. As a result of that mindset, divers will unlearn/forget/ignore basic diving practices such as proper gas management and buddy skills.

Take care.

Mike

PS. Think about all the things that would have to go wrong and/or ignored to really warrant the use of a pony on a recreational dive, and then reevaluate the real risk involved. After that, ask yourself if you are actually introducing a real solution, or just introducing another potential problem.

 

[The Chairman]

Hey Jackdav,

Your bio does not list your cert level, so I can't be certain. However, your question and the title referring to it as a "novice question" makes me feel you are probably a fairly new OW diver. I apologize in advance if my inference is wrong. That you are thinking in terms of safety for you and others SHOWS me that you are on the right track. You are willing to accept the responsibility that so many others shirk.

That being said, probably the most cost effective way to increase your safety and comfort in the water is NOT a pony bottle, but more training and lots more practice. Become an advanced open water diver, and then move on to rescue diver for the best cost/safety ratio. This will not only help you to respond to problems, but most importantly teach you HOW TO AVOID THEM. Prevention is ALWAYS the best solution.

Like fishing gear, the first thing dive equipment has to do is to "catch" the diver. Whether it works or not, provides more safety or not is almost irrelevant. If they can create a need within you or satisfy a phobia, they will have sold their stuff. While not all bells and whistles are "junk" and some are even appropriate in the more advanced diving, most will add task loading to your dive and dilute your ability to see and respond to emerging situations. KISS... Keep It Simple Stupid. Learn the gear you have now intimately BEFORE you go add more expensive gear. Sure, it all looks sweet, and it is so, so tempting, but enjoy the dive without all of that crap hung all over you. There will come a time when you will need it and these companies will sell you even slicker versions than what they currently have.

:tease:

 

[large_diver]

Before we totally squash the pony idea.....

Many of the anti-pony replies on this board tend to recommend good buddy diving (being one and having one) and proper gas management as the ultimate solution to underwater problems, OOA emergencies, etc.

This begs the question -- for rec dives to, say, 100 feet without a pony....

How much gas do you have when starting your ascent? Your buddy is right next to you. In an OOA/equip. failure emergency, would one of these tanks be able to get both of you to the surface safely, with slow ascent rate and safety stop?

Just looking for a little constructive debate.