73 replies to this topic

[gcbryan]

Stage mounting a pony, in other words carrying a stage with the same gas that you are diving in your back tank(s),

ok everything made sense except the stage mounting a pony. I am not sure what you mean by that. Could you explain that one a little better.

thank you

He means to sling it so that it is hanging more of less under your left arm as you would carry it if it contained your deco gas.

I backmount but I would never use it without a SPG clipped off where I can read it just like I do for my main tank. For what it's worth (regarding Trace's comments) I have a Sherwood reg on my pony bottle with the dry bleed system and I keep the bottle turn on. The amount of air it uses is virtually undetectable.

[ScubaDadMiami]

I know of one death personally that was the result of no gauge on a pony bottle. Regs freeflow and if you aren't aware of it then you'll find you have less gas than you think and no gas if you need it. If the bottle is on your back and you can't reach the valve, you'll have to leave the valve in the ON position. This will allow all gas to escape from the bottle if a freeflow occurs or a leak at the A connection (a.k.a. "yoke") could go unnoticed.

While I am not aware of a death, I can tell of an experience where the diver lost all gas due to unnoticed free flow of "pony" bottles. However, luckily, someone (who had a side slung bottle!) was able to pass it to the diver, and was able to abort, but safely complete, the remainder of the dive using his back gas and an additional deco mix. When you plan for thigs to happen, there are ways for everyone to make it back alive.

My point is, diving with a pony back mounted can cause, in addition to the entanglement hazards already mentioned, the additional failure of an out of gas situation should there be equipment problems or an unnoticed free flowing regulator. This is why the diver should pressurize the system before entering the water, shut it off, then pressurize again after making the decent. This will cover any gas lost during entry, preventing water entry into the low pressure hose and the regulator first stage. From that point on during the dive, simply turn on and off the valve every number of minute that pass, making sure to keep the system pressurized. This way, you will loose minimal gas if gas does get lost, and you will know that the system is working properly for when you will need to depoly it.

Having a gauge with a six inch hose will keep the gauge hose from getting in the way, and it allows the diver to know just how much has remains in the tank. I am in favor of carrying them but doing so properly.

Back mounting the bottle, and leaving the pressure on opens the diver up to one of these lost gas scenarios. I wouldn't do it this way.

I've seen people use Sherwood regulators with dry bleed systems on pony bottles and leave them in the ON position. This means gas is always escaping.

The amount of gas lost in an hour of diving is somewhere about a mouthful. It really does not contribute to any significant gas loss. Of course, getting a diaphram regulator with a sealed first stage does not require the bleed of the Sherwoods. The Sherwood design is used to prevent water entery into the first stage of the regulator since it is not sealed in the first place. On the other hand, I would not worry too much about the loss of gas from the Sherwoods. They can still be shut down and then pressurized every once in a while during the dive. That will keep them bubbling but not allow large gas loss through free flowing.

For those that don't dive in high currents much, you would be surprised at how much gas a regulator can lose from free flowing in strong currents. Scootering against these currents, I have to actually adjust my regulator, effectively detuning its awesome performance, just to prevent the currents from depressing the purge valve. The effect can easily go unnoticed since the current will blow the bubbles behind you rather than where you will notice them. Slinging a bottle helps keep much better track of this than does using a back mounted pony bottle.

Stage mounting a pony, in other words carrying a stage with the same gas that you are diving in your back tank(s), allows you easy access to your valve's handwheel so you can leave the bottle turned off until you need it, easily allows you to look at the SPG of that bottle, and easily allows you to remove that bottle to pass it to another diver, untangle it, or take it off before climbing a boat ladder or walking back to your vehicle. You can also hit sharks with it if they become aggressive. I realize that's far-fetched, but it just dawned on me that if I'm not holding a camera my stage bottle is ideal so I thought I'd mention it.

I have, unfortunately, come within a second of testing my need to bump an aggressive bull shark that was charging me while I still had a lengthy deco obligation to complete. As the shark charged me, I reach for my deco bottle, unclipped the back clip, swung the bottle around, and the shark stopped charging. This all happend in a split second. Honestly, if the bull shark had continued the charge, it would have been a real horse race finish to see if I would have completed my bottle removal enough to bump him with it before he had gotten into me with his attack. The whole incident was prettty scarey, and this shark was probably a 10 foot bull. I have witnesses even on this fish story!

[gcbryan]

I would only add that this whole turning on and off and on and off of a pony bottle makes sense only if you realize that when it's a deco bottle you absolutely have to have that gas to complete your dive and it isn't meant to be used as a bailout. As a matter of fact it can't be used as a bailout until you have already reached 20 fsw in most cases.

It doesn't make nearly as much sense for a bailout bottle with a proper SPG. As far as needing it slung for use to protect against sharks please see my other post regarding weak arguments.

Edited by gcbryan, 18 December 2005 - 02:38 AM.

[WreckWench]

I carry a 19cf pony that I used to back mount (meaning I attached it to the side of my primary tank) but found that it threw me off balance and that once when I needed it (I had forgotten to turn it on) that I could not reach the bottle to turn it on under water.

I then tried 'slinging' it as the techies do and found that I was not thrown off balance as it was closer to my center mass and I could easily turn it on if I forgot to do so at the surface and I could take it off if I needed too or even give it to another diver in need if necessary.

I think Trace has made some excellent comments about what size to get and if you are even remotely contemplating the idea of more technical diving then he makes excellent points. If more people did standardize on these sizes for the reasons he has stated then the price of these sizes would go down which would be yet another reason to consider those sizes.

gcbryan also makes an excellent point. If you do not contemplate doing more technical diving then if it is a trade off between 14 or 19cf then going with *more* gas is better in my book.

The real answer is that it depends on what you wish to accomplish, what type of diving you'll be doing and the beauty of this community and others like this community is that you can get a diversity of ideas and experiences to complement the knowledge you already have. And depending on what you want to do...what kind of diving you'll be doing...and where you think you might go with your diving...you can derive an answer that is *right* for you. You certainly have some awesome talent here giving you some awesome advice, suggestions and insight.

(And if you want to learn more, let us know...we offer a very unique 'intro to tech' clinic that was designed for divers curious about *all this tech stuff*! It will take all the questions you have and others have had and will discuss various types of equipment, diving styles and all other aspects of technical diving in a hands on weekend where you get to learn and apply the principals you've learned so you can make good decisions for yourself.)

Note: We encourage any member that wishes to share their thoughts and ideas and beliefs on ANY subject related to diving on this site to do so. We ask that you do so in a manner that fosters learning and respect, is courteous to your fellow diver, and contributes to the positive nature of this site. You may disagree with things that are posted and if you do then please post a positive counter response. To simply *flame* or *shoot down* or *dismiss* something without providing a reason or without the benefit of an equally educational response is not conducive to the goals and objectives of this forum. In other words, if you don't have something nice to say, please don't say it. If you disagree with one of the posts made or you don't understand them, then please say so but do so in a manner that will help the readers of this forum learn something. To simply discredit, dismiss or reject something via a post serves no purpose other than to be inflammatory and will be taken as such. Thank you all for your thougthful participation and I look forward to learning more from this and other threads on the site. -Kamala aka Wreck Wench

[TraceMalin]

Stage mounting a pony, in other words carrying a stage with the same gas that you are diving in your back tank(s),

ok everything made sense except the stage mounting a pony. I am not sure what you mean by that. Could you explain that one a little better.

thank you

This site might explain it more simply:

http://dir-diver.com...le_rigging.html

I forgot to add that you clip the bottle off to a chest D-ring at the neck and a hip D-ring at the tail of the bottle. I wear mine on my left side for several important reasons.

Trace

Edited by TraceMalin, 18 December 2005 - 02:08 AM.

[TraceMalin]

I would only add that this whole turning on and off and on and off of a pony bottle makes sense only if your realize that when it's a deco bottle you absolutely have to have that gas to complete your dive and it isn't meant to be used as a bailout. As a matter of fact it can't be used as a bailout until you have already reached 20 fsw in most cases.

It doesn't make nearly as much sense for a bailout bottle with a proper SPG. As far as needing it slung for use to protect against sharks please see my other post regarding weak arguments.

Bottles can carry any gas you want in them. Most divers using stages, but not all, are using decompression gases. When using a stage, I'm either using a gas identical to that of my back gas or I'm using a gas with a higher O2 percentage. The most common stage gases are 100% oxygen, 80% oxygen, 50% oxygen with 32% and air often used when the back gas is nitrox or air. Only those divers using 100% are limited to a gas switch at 20 feet. 80% allows a 30 foot switch. 50% at 70 feet, 32% at 132 feet and air is good to 219 feet regarding CNS toxicity. To say you can't bailout until you're at 20 feet with a stage is ridiculous. Many of us are often using 50% rather than 100% as our deco gas because it allows the oxygen window to be opened sooner for Pyle deep stops. With that we can bailout at 70 feet. I've been there and dobe that when a buddy experienced a low on gas situation due to exertion. Since our plan called for a gas switch at 70 feet, we switched and ascended on our deco schedule even though we didn't technically have to do that. There are advantages and disadvantages to using either 50% or 100% and ideally they work better together, but if only taking one stage then you weigh the pros and cons of each. Oxygen is usually better, but it depends on your back gas, your profile, the conditions, and when you play around with the M values and deco software sometimes you are often surprised which gas is logistically better for deco.

For the recreational diver thinking of using a pony bottle, "stage mounting" it means wearing it slung as a stage bottle and carrying the same gas you using in your primary tanks or a gas with an MOD not greater than your maximum dive depth. So, air/air, air/nitrox 32, nitrox 32/nitrox 32 would be the gases to use for most recreational diver.

If you read my post you'd see that I said "far-fetched" in regard to another use of a stage bottle. I've had sharks (not the sissy ones) become aggressive around me several times in the past. It bothers me less when I have a video camera in my hand because I know if one gets too aggressive I have a non fleshy bumper at the ready. I had an "ah-ha" experience while watching a shark documentary on TV and typing the stage bottle post. So, I added it. If you want me to get into more detail on why I posted that, it was to make Kimber laugh since she's shark bait... um... I mean a shark wrangler now, more so that to add it to my argument for stage mounting.

Leaving a pony bottle on only invites gas loss. It shouldn't be done. That's why a valve on any pony needs to be reachable. Carrying it as a stage makes more sense in every way regarding safety and it's more user friendly in that position.

Trace

[TraceMalin]

Note to all regarding Sherwoods: I have used my Sherwood reg on a stage several times to experiment with gas loss. I lost several hundred psi during the course of the dives through the dry bleed. I pressurized the reg every time the SPG hit zero. Granted, I do longer duration dives than most recreational divers, but I felt that the amount of gas lost was too much to warrant a Sherwood as a stage/pony reg. It was more than a mouthful.

Trace

[gcbryan]

Note to all regarding Sherwoods: I have used my Sherwood reg on a stage several times to experiment with gas loss. I lost several hundred psi during the course of the dives through the dry bleed. I pressurized the reg every time the SPG hit zero. Granted, I do longer duration dives than most recreational divers, but I felt that the amount of gas lost was too much to warrant a Sherwood as a stage/pony reg. It was more than a mouthful.

Trace

Not to belabor the point but my comments regarding deco and 20 fsw was just short hand to not have to go into every possible gas/limit possibility.

I have slung a pony and could easily do it if necessary. I just found that for my purposes it wasn't necessary. I also like to take pictures underwater and sometimes get rather low to get a shot. It doesn't help to have a bottle hanging down between my body and left arm.

All or most of your points are valid just not necessary in every case. If my pony bottle with Sherwood reg uses 100 psi on a dive, no problem. If that was deco gas I would possibly reconsider.

Actually I would suggest to the original poster or to anyone else to try both methods and to decide for themself. I tried a BP/W, liked it and bought one. I tried to sling the pony, could do it but didn't like it was well as the way I had been doing it. I would recommend that approach to anyone.

Edited by gcbryan, 18 December 2005 - 06:54 PM.

[drbill]

I have slung a pony and could easily do it if necessary. I just found that for my purposes it wasn't necessary. I also like to take pictures underwater and sometimes get rather low to get a show. It doesn't help to have a bottle hanging down between my body and left arm.

Precisely the reason mine is backmounted. I slung the pony in the beginning, but it got in the way too frequently when I was lying low trying to get shots or when I tried to shift my arm.

The balance issue was largely resolved by counterweighting on the opposite side of my body.

I also mount mine upside down and low on the primary tank. Access to the valve is simple that way and it also allows me to wedge part way into a crevice to get footage before I reach the "double wide" part of my tanks..

If I spent most of my time midwater, I'd probably sling it for better balance.

Edited by drbill, 18 December 2005 - 09:50 AM.

[gcbryan]

I have slung a pony and could easily do it if necessary. I just found that for my purposes it wasn't necessary. I also like to take pictures underwater and sometimes get rather low to get a show. It doesn't help to have a bottle hanging down between my body and left arm.

Precisely the reason mine is backmounted. I slung the pony in the beginning, but it got in the way too frequently when I was lying low trying to get shots or when I tried to shift my arm.

The balance issue was largely resolved by counterweighting on the opposite side of my body.

I also mount mine upside down and low on the primary tank. Access to the valve is simple that way and it also allows me to wedge part way into a crevice to get footage before I reach the "double wide" part of my tanks..

If I spent most of my time midwater, I'd probably sling it for better balance.

I think you've hit it on the head. Viz is such that mid-water is never where I am. Even if I'm not taking pictures I'm looking under logs for octo's, cling fish etc. Slinging in great viz may be different.

[TraceMalin]

Slinging bottles and carrying them is common in the northeast. I can carry one to three through a wreck or cave and through tight places most people can't even believe a human can fit. It's a skill that one develops through practice just like any other. Ultimately, diving comes down to practice. A diver needs to practice with equipment just like any other sport. Like many sports there are the dabblers on one extreme and the avid on the other. In diving, if something is difficult to do then most divers say, "It's not right for me," rather than realizing that practice will overcome what might seem difficult or more of a pain in the butt, but once adapted to, the skills and gear placement work exceedingly well. Few people ever take one shot at a basket and say, "I can't play basketball." Most divers who master basic tech skills and begin to use the equipment the way I and others advocate would never think of going back to the ways we used to dive. Today, because of GUE and other tech agencies and instructors, many people such as Perrone can adapt these discoveries right from the beginning of their diving careers. For others, such as myself, the process of adaptation has taken longer and followed many roads. I've accumulated enough junk over the years to piss me off. The only good that came from trying various methods of diving is that I can speak from experience when I now advocate a way of diving that others resent. I once resented it myself. I argued with my GUE instructors over just about everything and challenged them. While I don't accept every aspect of DIR (which is why I'm not a DIR diver), the basics are very solid. I set out to achieve the same skill level as Andrew Georgitsis and during that journey, I began to understand the things he tried to get through my head when I was a pain in the butt student. I used to think carrying a stage was a PITA. I tried to carry the smallest stages possible which is why I tried 30's rather than 40's. BZZZZ... thanks for playing, Trace. The 40's ride better. I thought carrying an 80 stage was too big and intimidating. Bzzzz... much better balance when using my Pro 14 and it just rides so smoothly. The things that others take as being preached have been tried and experimented with by those who broke ground, found out 40's rode better than 30's etc. found out 50% was more effective than 40% for deco, etc. Often things seem "wrong" until you really try thenm yourself and often you may be experimenting with an incorrect mounting, bottle size etc. For example, if someone carried a 30 stage and said he or she didn't like the way the stage rode, I'd agree. It seems to want to nose dive. THat's because once rigged the center of gravity is farther forward and the valve is heavy. Go to a 40 and not only do you get more gas, but the extra bottle length and weight of the compressed gas will better balance the bottle. Why is it that when we are going to football, baseball, or hockey practices we really want to get better and we work hard accepting the advice and trying the advice of our coaching staff, but when it comes to diving we dismiss advice from the more experienced? Is it because diving is an invisible sport in which we rarely see truly great diving, but think we are good? If you are throwing a ball 25 yards but it's sloppy and you've never seen a perfect spiral, you may think you are good, but then, a football coach can just come along, grab a ball, throw a perfect spiral and then show you hand position. Then you practice it knowing it can be done. Is it about ego? Is it because the agencies have watered down training and tried to pump out instructors by the dozen to compete with other agencies and we have a perceived lack of proficiency in every c-card carrying diver and instructor? Or is it just online environments that don't foster learning and those of us with the experience, practice and training who know from experience how it all works and once had many of the same misconceptions put forward by others are just wasting our time?

Trace

[PerroneFord]

Trace,

I have 18 logged dives in my book. I was certified in 1994. Since that time, I have had opportunity to meet with, talk to, and in some cases dive with some very good divers and pioneers of diffent parts of our sport. Over my 11 year absence, I kept up with diving magazines, equipment, tecniques, etc. I read diving boards, kept up with the cave exploration in my area, etc. The problem I faced coming back to diving wasn't lack of knowledge or interest, it was lack of experience.

In nearly every endeavor that requires real skill, newer participants face two general kinds of experienced participant. There are the ones that look down thier nose at new participants even if they show promise, or are eager to learn. And there are those who teach, mentor, or otherwise guide new participants so keep them on a path to success. As a semi-professional coach (paid to coach, not paid enough to make a living from it) I often have to take in new players, and help them along these paths. So this idealology is not new to me.

Diving sometimes seems to attract rather affluent, strong willed, and occasionally arrogant people to it's ranks. Maybe it's the money. Maybe it's just the rugged individuality that the sport portrays. But for whatever reason, some of these folks absolutely cannot stand that someone relatively new might have some ideas or hold some beliefs that are contrary to their own. I have never failed to be outspoken about my beliefs in diving, or my other pursuits. However, I am a researcher and always have been. I spent over 3 years researching my gear, my training path, and looking for instructors so that when I returned to diving, I'd have a head start.

Some people eschew book learning. Or learning from the internet. Some people call that "internet diving". Well, call it what you want. The fact is, there are a LOT of well respected members of the diving community who all share VERY similar ideas and beliefs about our sport, and I intend to listen to what they have to say. I spent half an hour talking to Jarrod Jablonski a few months ago. Face to face. I came away with an impression that might not jibe with what some others feel. But that man has a LOT he can teach me, and I intend to learn all I can from him. My current instructor is not DIR. In fact, he has some VERY good reasons for not being DIR, but he is world reknown for what he has done in diving, and I intend to learn all I can from him too. Sometimes what he says doesn't jibe with GUE's training. We discuss it, and he lets me make my own choice after seeing both sides of the argument. He has been quite happy to guide my process of discovery in terms of my gear, my path in diving, etc. I don't feel I could have selected better.

When I was in school, I was told the earth was round, that man had walked on the moon, and the earth revolved around the sun. One thousand years ago, children were taught that the moon was in outerspace and no human could get there, the sun revolved around the earth, and the earth was flat and you would sail off the end of it. At some point, a lot of people much smarter than myself challenged these beliefs, and refuted them. However, I didn't set out to sail around the earth, fly to the moon, or measure the earths orbit around the Sun. I took them on faith. Much the same with my diving.

When someone has done 3000+ cave dives, has been on diving expeditions around the world, and is published the world over for what they have done under the sea, I generally take what they say with some weight. Some people are just obstinate enough to do the opposite to prove something. I have other things to do with my life.

[TraceMalin]

When someone has done 3000+ cave dives, has been on diving expeditions around the world, and is published the world over for what they have done under the sea, I generally take what they say with some weight. Some people are just obstinate enough to do the opposite to prove something. I have other things to do with my life.

I think I'm going to take that last sentence of yours as advice.

Trace

[drbill]

When someone has done 3000+ cave dives...

Holy mackerel... you mean there are real cave divers who have actually survived that many cave dives? I thought that was like believing in a flat earth! Just trying to add some levity here. Just remember... DIMW (Do It My Way).

[ScubaHawk]

When I was in school, I was told the earth was round, that man had walked on the moon, and the earth revolved around the sun. One thousand years ago, children were taught that the moon was in outerspace and no human could get there, the sun revolved around the earth, and the earth was flat and you would sail off the end of it. At some point, a lot of people much smarter than myself challenged these beliefs, and refuted them. However, I didn't set out to sail around the earth, fly to the moon, or measure the earths orbit around the Sun. I took them on faith. Much the same with my diving.

Just to keep you motivated to keep learning: The Earth is not round - it's got a huge bulge at the middle, The Earth does not exactly revolve around the Sun. They both orbit the center of mass of the two bodies. It's amazing the more you learn, they more exact things become - and the more you have to learn about them. (OMG am I a nerd or what) I think the mystery and the learning makes the whole shebang worthwhile. Once you stop questioning and learning, they might as well start shoveling the dirt.

Back on topic - -for the pros out there: What size pony bottle or "spare air" would you recommend? I want something that will cover my air needs, along with a safety stop(s), for an OOA emergency at 150'. Given moderate air consumption.