SPG or not

[Still Kicking]

Sure wish SCUBA valves had built in SPGs like SCBA.

Not me....i have seen too many smashed and mangled button gauges over the years. Just another headache.

Fire departments/fumigators etc. like the integral gauges for a visual check but the end user is not paying for the damage if they get damaged.

 

[Belzelbub]

Hahaha! Perfect!
Now let's start the entire discussion all over again for the fifth time, making sure to not read anything that was written in the previous ten pages, not to mention the six prior threads referenced on the first page. After all, we each have a unique perspective!

Well, the thread was quiet for about a month. Then someone woke it up. Who would do such a thing?

 

[grantmac]

Not me....i have seen too many smashed and mangled button gauges over the years. Just another headache.

Fire departments/fumigators etc. like the integral gauges for a visual check but the end user is not paying for the damage if they get damaged.

The Dräeger ones are damn near indestructible, never seen an issue with pretty brutal service.

 

[halocline]

You have obviously never broken and dislocated a shoulder. Really makes tank handling very difficult on that side of your body. Now, add a broken neck on the other side with nerve damage and lets see how you do. Over 60 and a bit overweight does not help much either. Nerve damage makes working out significantly more difficult if not impossible. Not all divers fit in a single category. Diving does relieve a bit of pain, so I will continue as long as possible with a back mounted pony because it is safer than no pony.

I’m sorry to read about your injuries, but that has nothing to do with the difference between back mounting and slinging a bail out bottle. I suspect I’m older than you and while I’m pretty healthy and fit for my age, I’ve definitely dove with injured and disabled people. An extra tank on your back is very, very unlikely to be the most comfortable solution. I know this because I have dove with single tanks, double tanks, side mount tanks, ponies, stages, deco bottles. Have you ever tried slinging a pony, maybe with some instruction from a professional? If not, then I suggest you don’t knock it until you try it.

BTW, there is no real evidence that using a pony, especially a back mounted one that you don’t have full access to, increases safety on single tank recreational dives. You personally might feel safer, and that counts for something, it helps you to enjoy your dive with less anxiety. But there are way too many factors to say that it’s actually making you safer. There are arguments that it increases danger for some divers, again probably no statistical evidence, but it’s a robust discussion.

 

[KenE]

I’m sorry to read about your injuries, but that has nothing to do with the difference between back mounting and slinging a bail out bottle. I suspect I’m older than you and while I’m pretty healthy and fit for my age, I’ve definitely dove with injured and disabled people. An extra tank on your back is very, very unlikely to be the most comfortable solution. I know this because I have dove with single tanks, double tanks, side mount tanks, ponies, stages, deco bottles. Have you ever tried slinging a pony, maybe with some instruction from a professional? If not, then I suggest you don’t knock it until you try it.

BTW, there is no real evidence that using a pony, especially a back mounted one that you don’t have full access to, increases safety on single tank recreational dives. You personally might feel safer, and that counts for something, it helps you to enjoy your dive with less anxiety. But there are way too many factors to say that it’s actually making you safer. There are arguments that it increases danger for some divers, again probably no statistical evidence, but it’s a robust discussion.

Until you have walked in my shoes, and the shoes of every other diver who has an opinion different than yours, then you should not be so determined that your opinion is the only correct answer.

I have tried all the options you mentioned and several others. I am diving the most comfortable option.

Why would a back mount pony be any less safe if you don't have access. Most recreational divers don't have access to their main tank, why would the pony need to be any different? I believe most folks would agree that a redundance source is safer than not. You will need to explain yourself much better.

 

[Badger7]

Most recreational divers don't have access to their main tank, why would the pony need to be any different? I believe most folks would agree that a redundance source is safer than not. You will need to explain yourself much better.

Access to the valve. Most recreational divers should be able to just-barely operate their main cylinder valve as necessary while kitted up and when in the water. I don't know if the same could be said of a backmounted pony unless you're double jointed or mount it inverted, and even so you're much less likely to notice a leak or free flow until your redundancy has bubbled away. Feathering a pony valve in response to reg free flow issues is a less realistic option when backmounted as well.

With the pony slung in front, you have full access to the tank valve, so you can turn on the valve, check the pressure, breathe the reg, and then turn off the valve so you're far more certain of available gas in case of emergency. You're also far more likely to notice any leaks or free flows on the pony if it you have easier frontside access. I don't think anyone could disagree that a completely self-contained pony that can be clipped off with two boltsnaps gives you and your dive buddies far more options if something goes sideways than a cylinder fixed to another cylinder on your back. Finally, a full pony with a brass reg is at least a couple pounds negative, which trim better hanging below your CG in front than it does perched on the back.

There's no right or wrong answers here, but some solutions have a few more pros than cons. I'm sure no one is going to make you change your mind, thats not the goal here, just sharing why I switched from diving a back mounted pony when diving a "single" tank configuration in favor of slinging a 40 instead - more options and better access.

 

[halocline]

Until you have walked in my shoes, and the shoes of every other diver who has an opinion different than yours, then you should not be so determined that your opinion is the only correct answer.

I have tried all the options you mentioned and several others. I am diving the most comfortable option.

Why would a back mount pony be any less safe if you don't have access. Most recreational divers don't have access to their main tank, why would the pony need to be any different? I believe most folks would agree that a redundance source is safer than not. You will need to explain yourself much better.

First of all, I did not say that my opinion is ‘the only correct answer’. Please try to not be defensive, this is a friendly dive-related discussion both for your benefit and for the benefit of people reading now and going forward that might have similar questions or ideas.

Second, you said:

“I have tried all the options you mentioned and several others”

That’s a little hard to believe because there are not ‘several other’ options beyond what I mentioned. I guess there’s free diving, rebreathers, and surface supplied. But if you’ve tried a slung pony, with the assistance of a trained professional who knows how to rig, carry, and deploy one, and you didn’t like it, fine. It’s your diving, you can do what you want. But you’ll never convince me or others who have more experience than either of us that it has anything to do with injuries or physical limitations.

The ‘is a pony safer for recreational diving’ discussion is a big one, I have been involved in several threads in past years if you have any real interest in my opinion. The bumper sticker version of my opinion is that diver judgement and behavior is what primarily determines safety, not carrying extra equipment. This includes clearly understanding the limits of recreational diving and dive training. If you feel that you need a bailout bottle in that environment, it’s worth asking yourself why, and I mean specifically. Because clearly the most comfortable gear set up for you would be a single tank only, unless there’s something strange about your injury that makes strapping an additional metal cylinder onto the side of your tank, dealing with the extra weight out of the water and the balance in the water, the extra entanglement risk, and managing an extra 2nd stage hose that you cannot physically trace to its source, ‘more comfortable’ for you.

That’s all I have to say on this topic. Best of luck.

 

[KenE]

Access to the valve. Most recreational divers should be able to just-barely operate their main cylinder valve as necessary while kitted up and when in the water. I don't know if the same could be said of a backmounted pony unless you're double jointed or mount it inverted, and even so you're much less likely to notice a leak or free flow until your redundancy has bubbled away. Feathering a pony valve in response to reg free flow issues is a less realistic option when backmounted as well.

With the pony slung in front, you have full access to the tank valve, so you can turn on the valve, check the pressure, breathe the reg, and then turn off the valve so you're far more certain of available gas in case of emergency. You're also far more likely to notice any leaks or free flows on the pony if it you have easier frontside access. I don't think anyone could disagree that a completely self-contained pony that can be clipped off with two boltsnaps gives you and your dive buddies far more options if something goes sideways than a cylinder fixed to another cylinder on your back. Finally, a full pony with a brass reg is at least a couple pounds negative, which trim better hanging below your CG in front than it does perched on the back.

There's no right or wrong answers here, but some solutions have a few more pros than cons. I'm sure no one is going to make you change your mind, thats not the goal here, just sharing why I switched from diving a back mounted pony when diving a "single" tank configuration in favor of slinging a 40 instead - more options and better access.

I have talked to many about valve access and most say they don't even try. I did this when I realized that I could not access my valve and was trying to determine the validity of the need. After many years of diving, yet to find a need to access the valve on either. Gas loss on either should be seen by buddy and with AI on pony. So, again, no need to have it in front of me, which is not an option.

I don't disagree that there are advantages and disadvantages for both, and it has been argued here extensively. My contention is that slung is not the only option. My response was to someone indicating that a pony is not beneficial, and definitely not if back mounted. I find this ridiculous.

 

[KenE]

This is not true, and it makes me question your knowledge and experience in this regard. I can certainly reach my main tank valve, I've done it once or twice when I splashed with the valve off. The same cannot be said for a backmounted pony which sits too low for most or all divers to reach on their own.

Your statements about a backmounted pony versus slinging it because of injuries don't make sense either. A slung pony can be clipped on just prior to splashing at the entry point, and removed immediately upon reaching the exit point, be it boat or shore dive and carried separately to reduce weight, whereas a backmounted pony is much more problematic to separate from the rig so it usually isn't.

And finally to say a backmounted poiny being superior to no redundant source, while being true, does nothing to support the argument that backmounting is a better way to go versus slinging it.

You can rationalize and justify your decisions to yourself any way you want, but don't expect them to go unchallenged by those who know better.

It is much easier to carry a pony on the back then in the hand. It cannot be slung when out of water due to pressure on the left side. Once the rig is on my back I can't tell the difference if it is there or not other than a bit of weight. Adding something else to carry from truck to water is a problem with poor arm strength.

I was not saying that one is superior to the other. My response was to someone indicating that a redundance source is not needed and definitely not if back mounted. So, I agree with you, slung or back mounted, a pony is safer than nothing. I don't care if someone wants to back mount or sling, it is up to the diver.

I am not rationalizing or justifying anything other than I have tried it all, and this works for me. It was the other comments that are trying to justify that slung is the only viable option.

 

[Nick_Radov]

One less failure point.
One less hose to replace every few years.
One less thing clipped off.

When they do fail, they fail the wrong because they stick, indicating you have more gas than you do. AI fails in a safe manner.

Since you have to check the SPG every 5 – 10 minutes anyway, it should be obvious when it's stuck. When using double back tanks with an isolation manifold then if you see the SPG reading appears stuck that can also indicate that your isolator value is closed.

If you don't trust the air integration, then why use it? Stick to an SPG.

My fins could break, I don't carry an extra. My mask could break, my wetsuit, et cetera. I don't carry extras.

Proper fins with spring straps really can't break. Masks with proper straps aren't really breakable either, but can be knocked off and lost so it's always a good idea to carry a spare. Takes up minimal space in your pockets.

If I were exclusively a solo diver I wouldn't carry an extra second stage either. Redundant first stage makes the most sense.

If your SPG gave a you a drastically different reading than the AI, what would you do?

Start with a flow check, of course. Depending on the results then most likely abort the dive, and possibly also take a teammate's long hose to start sharing gas.