How to: Air Sharing In A Scuba Diving Emergency
Don’t Get Gas Mugged!
I see lots of debate on scuba diving social media about optimal regulator configurations for air sharing. Divers debate the pros and cons of ‘traditional’ octopus, AIR2 systems, using the long hose, spare air and pony systems, primary share versus secondary share, options for securing alternate air sources, quick release methods etc etc etc
Invariably, the issue of “getting mugged” for air is raised. That being, where an out-of-air diver gets panicked by air depletion and ‘mugs’ the donor by, without warning or signal, unexpectedly ripping the regulator out of their mouth. The general consensus is that this should be considered a ‘normal’ or predictable scenario. Some instructors even counsel students to expect this.
If a diver gets ‘mugged for air’ then it points to a major failing in situational awareness and the buddy system. It should never happen.
Assume stress when air sharing
That doesn’t presume that novice-to-intermediate divers won’t get stressed or panicked by air depletion. It’s wise to assume that inexperienced divers will freak out if their air supply ceases unexpectedly. Stress management to air depletion is not something commonly taught in recreational scuba diving classes anymore.
Whilst ‘dive professionals’ and technical divers receive some training in this respect, the greater majority of scuba divers can only develop calm out-of-air responses with significant time and experience.
Apply the buddy system diligently
The buddy system is a core principle in nearly all recreational diving training. It is, supposedly, our first line of defence against potentially fatal accidents. However, the system needs to be diligently applied if it is to be relied upon.
Sadly, that diligent application is increasingly rare. We live in an age of delegated personal responsibility, where the ‘dive master’ is all too often relied upon to keep us safe, to observe and supervise us, to assist with our emergencies. We have a ‘shepherd’, so we’re encouraged to dive like sheep.
The concept of the Open Water diver being qualified to dive “independently and without professional supervision; with a buddy of equal, or higher’ qualification” has ceased to exist in many diving locations around the world. It’s a sad state of affairs and it can lead to tragedy.
Prevent the need for air sharing by proactive behavior
With specific regard to out-of-air emergencies, the buddy system should primarily be viewed as a preventative safeguard.
Accident prevention through the buddy system can never happen if basic situational awareness is not achieved. Every diver has the capacity to check their own air during a dive. At this time, it is simple to also check/confirm the air of their diving buddy.
Scuba divers can only get ‘gas mugged’ if they are diving in dreamland; switched off and applying zero situational awareness. Getting a regulator ripped from your mouth is definitely a ‘karma occasion’.
Obviously, in an ideal world, the diver will know all about SAC/RMV rates. They will enter the water with an accurate prediction of my air consumption for a given depth and time. Their buddy/team will do likewise. No surprises that way.
But the public increasingly demands quicker, cheaper and easier dive training courses; so the ‘ideal’ methods get swept aside and deferred to more ‘advanced’ stages of diving education. You get what you pay for.
Learn gas management skills
For most diving agencies, entry- to intermediate-level divers aren’t taught how to calculate and monitor SAC/RMV rates. They, therefore, need a different approach… something simple, but effective.
I don’t have gills and I don’t want to drown on a dive, so my finite and exhaustible air supply is a major concern to me when I am diving. That means I routinely check my air over the course of a dive. For an average recreational dive, let’s say 60 minutes, I will probably check it 4 or 5 times. The frequency of checks obviously increases as the dive progresses and my air supply gets lower and more critical. I suggest you endeavour to do the same.
To prevent the chance of an out-of-air emergency within my buddy pair or team, I simply need to inquire what the other divers’ air is whenever I check my own. It’s a case of simple communication that is taught right from the start on Open Water training. I check my air, I check your air. I compare. It’s an easy protocol to remember.
If I know my air level and your air level, then it’s not rocket-science to apply the most simplistic deduction and allow some anticipation of air consumption. I can easily identify the relative air consumption between myself and another diver.
For example, when you check air over the course of a dive;
- You have 180 bar, your buddy has 170 bar.
- You have 140 bar, your buddy has 120 bar.
- You have 110 bar, your buddy has 90 bar.
- You have 90 bar, your buddy is likely to have ______ bar?
You can quickly work out if your buddy’s air consumption is higher, or lower than yours. Furthermore, over several checks, you can see a pattern that gives a very loose approximation of how much difference there is between your air consumption. This allows the most basic predictions to be made. Those predictions are sufficient to prevent most out-of-air emergencies.
In the example above, you can anticipate that when you reach 90 bar, your buddy should now be very close to their reserve air level (50 bar). You will know the dive is nearly over. It is time for you to start paying close attention to your buddy, to confirm their air and start your ascent.
Predicting gas consumption = less air sharing emergencies
In the space of the dive, you can predict that when you reach 90 bar of air remaining, your buddy is likely to be at, or close to, their own air reserve level. That becomes your warning trigger. Once reached, you have to do something about it.
Having anticipated that your buddy is probably getting low on air, you should raise your level of buddy observation and focus. You should get closer to them and should quickly confirm that your alternate air source (of whatever configuration) is available, working and ready to deploy.
The worst case scenario is that, even with anticipation, your buddy might still run out of air. That can happen for several reasons; such as some SPGs not reading accurately below 50 bar / 500psi, a poorly performing regulator that can’t deliver at lower intermediate pressures, or an unanticipated ‘spike’ in breathing rates.
If you are pro-actively observing, then you will immediately notice any symptoms of air depletion stress in your buddy; shortened breathing, wide eyes, rapid head and arm movements, the desperate grab for an SPG… and your alternate air source will be rapidly deployed and waiting a couple of inches from their mouth. Salvation is immediately on hand, and a panicked diver scenario is avoided. The air sharing ascent should be calm, methodical and satisfying…. just like it was when you practised it in training.
The best case scenario, of course, is that you can identify a low-on-air situation and pro-actively offer to share air before an out-of-air emergency even occurs. Personally, I’d rather donate air whilst my buddy still has a little air remaining. Anything less than 35 bar in your cylinder and I will physically offer my alternate air source for the ascent. Take it or leave it, but prevention is better than cure.
If air sharing surprises you, don’t blame the victim
No exceptions, no excuses. If another diver reaches a stage where they are panicking from unanticipated air depletion; and feels the urge to ‘mug’ me of my primary regulator, then it is equally MY failure as their buddy or teammate.
The buddy system relies on three critical attributes; observation, awareness and anticipation, especially in regards to air sharing. If you allow weak situational awareness to impede the buddy system then there can be negative consequences. Divers have died because of unanticipated, botched air sharing attempts.
Anticipating the need to air share stops a mistake from becoming an emergency and then turning into a catastrophe. The difference is all about avoiding diver stress and panic. There’s something very reassuring; and stress nullifying, to know that your buddy ‘has your back’ and is ready and able to give you life-sustaining air without notice or delay.
About the Author
Andy Davis is a RAID, PADI TecRec, ANDI, BSAC and SSI qualified independent technical diving instructor who specializes in teaching advanced sidemount, trimix and wreck exploration diving courses across South East Asia. Currently residing in ‘wreck diving heaven’ at Subic Bay, Philippines, he has amassed more than 9000 open circuit and CCR dives over 27 years of diving across the globe.
Andy has published many magazine articles on technical diving, has written course materials for dive training agency syllabus, tests and reviews diving gear for major manufacturers and consults with the Philippines Underwater Archaeology Society.
He is currently writing a series of books to be published on advanced diving topics. Prior to becoming a professional technical diving educator in 2006, Andy was a commissioned officer in the Royal Air Force and has served in Iraq, Afghanistan, Belize and Cyprus.
Originally posted 2018-11-05 06:10:51.