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Out Of Gas
BobHalstead - 4/29/2013 8:15 AM
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Category: Educational
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By Bob Halstead

“There I was, alone, 30 metres down the drop off. Grey reef sharks menaced my left, their chilling eyes glued to my succulent thighs. Then, to the right, I was stunned to see a huge Tiger shark, jaws agape, lunging towards me. Suddenly a giant tentacle reached up from the deep and grasped me around the ankle. Just then I realised that no more air could be sucked from my regulator ….. “

Let us suppose that you find yourself, through bad luck or your own stupidity or whatever, at 30 m. with no air. What should you do to get to the surface safely? Are the skills recommended in your Scuba class really sane?

I first started to feel uneasy about alternate air and buddy breathing when I noticed more and more discussions about whether the donor should be in front or to the side, how many breaths to take, which regulator should be passed and where the alternate regulator should be carried and which hand should go where and …. Well you know what I mean. You see I was still trying to figure out how I was going to find my buddy.

So I became the expert on Emergency Swimming Ascents, (or, for the lazy, drop your weights and make a Buoyant Ascent). To survive these you need good breath control and tolerance for carbon dioxide build-up, and you got these by practicing skin diving. I am a pretty fair skin diver so coined the rule “Never dive deeper than twice the depth you can skin dive to”. This was taken seriously by some silly plagiarist and published in a book on solo diving. The trouble with these ascents was that although I was confident I could reach the surface after “no more air could be sucked from my regulator” I could not figure a way of doing a decompression stop on the way up, and I really like decompression stops on every dive – which is probably why, after more than 9,000 dives, I have never been bent.

The Emergency Swimming Ascent is a procedure that has such a high risk that instructor agencies advise never to practice it in the circumstance in which you may really need it, for example out of air at 30 metres. They advise practice from 6 – 9 metres but it is pretty well impossible to run out of air at those depths and if it is so risky to practice at deeper depths, why on why would you want to use it in an emergency? Seems dumb to me.

Emergency swimming ascents from 30 metres have become drills for consenting heroes in private oceans. They are skills that you just know the old pros can do but it is not something they are going to admit to practicing, especially to mere mortals. But there is a solution so simple that we do not have to learn or practice Buddy or Alternate Air source breathing or 30 m. Emergency Swimming Ascents at all because, if we are smart, we will NEVER have to use them EVEN with “no air” at 30 metres.

Of course it is much better not to get yourself in an out-of-air situation at 30 or even 10 metres – but you know, it happens, and is a principal cause of drowning and decompression illness. It is not always carelessness – my private survey of very experienced divers revealed that 21% of them had suffered sudden regulator failure, producing no air, at least once in their diving careers. (Many divers do not realise that some first stages contain an upstream valve that can completely shut down the air supply.)

However there is an answer – “Reaching down I pulled the pony bottle regulator from its clip on my chest and placed it in my mouth, purging before breathing normally and starting my ascent.”

Diving instructors stress the importance of “Normal” breathing and using SCUBA. If normal breathing is important then, surely, that must especially be used in an emergency. The only method that uses a normal ascent (not hanging on to another diver), and normal breathing, is using a sufficient independent air supply that you carry with you.

Can you practice the use of a pony bottle in the circumstances that you are likely to need it? – Yes! And you should do regularly. I have a “button” gauge fitted to my pony regulator so that I can easily check that the pony bottle is full before every dive. It is a wonderful secure feeling to know you have a completely redundant and sufficient air (gas) supply at all times.

I recommend it to you all, and I have to say that it is only the almost religious, and delusional, preoccupation with the buddy system over the years that has prevented pony bottles becoming standard gear. Who ever heard of a parachutist leaving his spare shute with his buddy?