Why extra air when solo?

[wetb4igetinthewater]

My Own Out of GAS Experience

 

[TMHeimer]

As pointed out way back, it's one thing to be solo diving at 20-30' without a pony--glorified snorkeling, and safer than snorkeling if you actually do get entangled. This is my typical solo shore diving. I occasionally have used my pony on deep boat dives with a buddy, and absolutely would use it there if solo. But that only happened once and is not in my plans. Then again I know an instructor who said she always dives solo to 100' and the only time she has a pony is when she finds one that someone lost down there.

 

[Divectionist]

Then again I know an instructor who said she always dives solo to 100' and the only time she has a pony is when she finds one that someone lost down there.

Two things.

1. Becoming an instructor is not difficult and should not be taken as an automatic sign of common sense or diving authority.
2. Solo diving to that depth without redundant air supply carries risks that everyone needs to assess for themselves. I call it idiotic.

Scenario:
Said instructor lady is cruising along at max depth and has accumulated a bit of a SurfGF and one of the disasters that can cause an OOA that an octo does not solve strikes. She keeps a calm head and CESAs from a respectable depth, makes it to the surface, takes a big breath in and suffers a bit of DCS. She is solo, so needs to get herself some help, if she can. Unfortunately, she did not find someone's lost pony bottle this time to ascent slowly, do a safety stop, and surface to dive another day.

The beauty of redundant equipment in this case is that if there is a given failure rate, say tank/reg goes bust 1 in 3000 dives (I made that up), then having two of each multiplies this, so instead of this being likely to happen every 3000 dives with potentially nasty consequences, it is only likely every 9,000,000 dives. That's a nice boost of probability on your side, for just a few hundred dollars.

If you own a pony, bring it on every dive. Dive the same configuration as much as you can. Practice deploying and switching to your pony reg, maintaining buoyancy. Practice doing it with your mask off.

 

[Diver below 83]

I’m forsure planning to use a pony for all my solo diving regardless of depth. I just haven’t worked an the ideal size combo for me yet.

 

[TMHeimer]

Divectionist, I couldn't agree with you more. Though I may take issue with saying that becoming an instructor is not difficult. Must define difficult and it varies per person. Took me a while to get through the DM course. But that has nothing to do with your good example of what could happen at 100'. I won't ever be bothering to attach up my pony for a 30' dive though.

 

[Fastmarc]

I won't ever be bothering to attach up my pony for a 30' dive though.

Just to add for those thinking of getting one, my experience differs from this. Though I haven't dived solo yet, when I decided to add a 19cf pony to my kit I took the advice here and slung it. Since getting it I take it on every dive. I dive mostly from a boat, small that requires back roll and doffing to get back in and I have to say for me it really is no bother to have it on every dive.

 

[jadairiii]

...makes it to the surface, takes a big breath in and suffers a bit of DCS. She is solo, ......

This is the reality of Solo diving (and I dive solo on occasion). All the back gas or pony bottles in the world will not help you if you suffer a debilitating medical emergency/DCS. Extra gas/air will not make your legs move, will not signal for help for you, will not keep your airway clear, will not swim you to the boat/beach or administer first aid.

A pony bottle may make you feel more secure but it can do very little for you,......... especially think.

 

[Nemrod]

I have become much more conservative as I passed the big 60 some years back. As my physical capabilities have diminished I have begun to impose limitations or requirements for additional equipment to offset. But there is no substitute for physical fitness. It is the last tool in my bag of tricks and when the SHTF it is what I reach for. Physical fitness makes up for a lot of bad luck, poor planning or even foolishness and foolhardiness.

The scenario described and the 100 foot CESA, well, would not have happened to me, because 1) I limit my dives now pretty much to 100 feet maximum (with exception) and 2) I use a redundant air supply per SDI solo requirements (with the exception for thirty-ish feet noted) and 3) I would not have been in or near deco when solo and 4) therefore I would have been able to make a 60 FPM ascent direct to the surface and 5) then drawing upon my training and physical fitness, finally 6) yes, if need be, I could do it.

N

 

[Perryed]

I agree with the OP. When I solo I stay within a breath of the surface. I make damn sure my equipment is in good order and I have always kept an extremely good eye on my air levels. If you wanted to cover every contingency in life that could kill you , you would never leave the house. It`s good for people that want a back-up to carry a redundant system , but that is up to the individual.

 

[markmud]

My Own Out of GAS Experience

Hi Kosta,

I enjoyed reading your article.

I liked your 8 points detailed at the end.

Both of my regulator system failures resulted in 1) leakage and 2) a freeflow (huge freeflow). I did not need to deploy my redundant system. One was while solo diving; and the other was buddy diving until the casualty, and then solo ascent and surface swim to the boat (after my so-called buddy noticed my octo freeflowing, he pointed towards the boat and then waved good bye).

Your #7 is interesting. I have not performed an octo or hog looped primary donate for real, so your take-away is duly noted. I do hog loop my primary and necklace my redundant second stage because I like it. I feel it is a better configuration for me. I avoid diving with newbs or instructors described in this post Why extra air when solo?.

I’m forsure planning to use a pony for all my solo diving regardless of depth. I just haven’t worked an the ideal size combo for me yet.

My ideal size pony is a moving target. This January I am travelling to a location where my baggage weight is an issue. Travelling with a 19 cf pony or a 30 cf pony is not an option. Solo diving is not allowed at this resort. I was told in writing that their DMs and instructors will take care of me and that they will gladly teach me to control my gas consumption through further training. I did not respond to their snarky and demeaning response. Probably came from this instructor: Why extra air when solo?

I will be buddy diving with very good divers. Usually, tech divers and instructors with a smattering of highly accomplished recreational photo divers. Really good divers.

I am taking my 6cf pony. It travels well. It can be filled easily with a transfill whip just in case the dive op will not fill my pony for me (it can be difficult to get one filled).

I like the 6 cf while buddy diving because sometimes my buddy becomes an SOB. Sometimes I want to check-out a feature and the group moves on (including my SOB). If I suffer a catastrophic failure, my SOB is an easy swim while holding my breath or on my pony. A host of highly trained and experienced divers are usually within swimming range. Or, I can easily abort to the surface with my 6 cf. I have practiced it many times (while being negative, while shooting an SMB, and always with a mask replacement drill or no mask at all).

While doing any other solo diving I like my 13 cf or 19 cf. I have used 30 cf ponies before. My choice is relative to logistics and how benign the diving is.

I don't know that there is perfect answer as far as size. A 30 cf pony that you can't dive with (because of logistics) or can't get filled is useless to you. If the SHTF, a redundant supply that delivers 6 minutes or 15 minutes worth of gas is huge.

The beauty of redundant equipment in this case is that if there is a given failure rate, say tank/reg goes bust 1 in 3000 dives (I made that up), then having two of each multiplies this, so instead of this being likely to happen every 3000 dives with potentially nasty consequences, it is only likely every 9,000,000 dives. That's a nice boost of probability on your side, for just a few hundred dollars.

I would love to see the actual stats for catastrophic primary system failures (no gas delivered, not OOA), based on number of dives. I will probably die before I get 3,000 dives logged. I have too many avocations to rack-up that many.

I think your numbers are closer than either you and I think is possible. For me, carrying a 30 cf pony on every benign dive for a scenario that is so remote is ridiculous. I could get hit by lightning, and probably not.

cheers,
,
m