Triggers of Dive Accidents

[Akimbo]

I have another take that requires donning full body armor. Statistics cannot prove or disprove, but I believe that the actual cause of most of those deaths was not out of air, it was panic resulting from inadequate personal ability to deal with being out of air.

I believe the biggest single contributor is teaching excessive dependence on equipment and the buddy system. IMHO, far too many divers I see are not sufficiently comfortable in the water, let alone with all the crap hanging off them. Most consider their BC as an elevator service.

I am not saying the buddy system should not be taught. I am not saying divers should not use BCs or octos. I am saying that divers should be taught that they cannot depend on their buddy for anything, but it is really nice if it happens to work out.

The unintended consequence of the octo is the misguided belief that buddy-breathing is no longer a useful training exercise. Buddy breathing is far from the point. The skill itself teaches watermanship, instills confidence, demonstrates personal limitations, and forces people to consider deep inside what the consequences of running out of are. Piling more gear on people may be good for shop sales figures and justify another merit badge, but does not solve the problem.

I believe teaching buddy breathing, (limited) harassment dives, and free ascents have much greater value than most ever realized.

 

[LiveBait]

First let me say that this is a great thread and excellent topic to discuss! I have enjoyed and got a lot out of most of the post and comments here.

Here are my credentials for giving you my opinion. lol
PADI OW cert.
Dive total 4
Even though I have very little experience in diving I think I can contribute to this thread a lot because I represent a person right out of OW training. I passed my training and did well. I would be willing to bet that my training course was about average. I am very certain that there are better and worse courses out there.

Here is what I know…
I know that air management is important just as important as DCS but, I have no idea how to manage it.
I remember several DCS test questions but, cannot remember any air management questions other than don’t do it.
I remember the best ways to do an emergency OOA ascent but not how to prevent it other than check your gauges and check them often.
I know that my buddy and I should start our accent with enough air in each or our tanks for both to make it up safely on one. I do not know how to calculate that. (I could look it up but I don’t have it memorized)
I know what SAC rate is but don’t know what mine is or exactly how to calculate it just like above.
I know I use air more like a top fuel dragster than an economy car and I use an Al80 exclusively.

Here is what I think…
This is just like running out of gas in your car. Some people never have a problem with it. They fill their tank as soon as it gets to a quarter of a tank. Others do it when the warning light comes on. Still others like to push it to the limits and run out. The only big difference I can see is that if your car runs out of gas it’s a pain in the butt! If you run out of gas 100’ down you could be dead. You might be able to say also that if your car runs out of gas it’s a pain but you learn from it and, you don’t get to learn from it in diving.
Another reason this reminds me of driving is because as a new driver I had a big four wheeled drive truck that got between 4-6 miles to the gallon(think sac rate). I thought I was a good safe driver and, I ran that thing out of gas a lot. I even purchased a emergency reserve 5 gallon gas can (reads pony bottle for cars).

As new divers we use more gas. We may be using smaller tanks AL80. We are less experienced but think we are well qualified.

I think it’s a matter of more training and, changing the way divers think about it. Dive boats should say “you should come up with enough air to get your buddy up from the bottom whatever that is! But we will take 500psi.” I think it should be a BIG deal if you run out of air and make it to the top ok like “WOW YOU JUST WON THE LOTTERY!! Maybe you should quit now while your ahead and alive!”
I don’t think taking cards away is the right answer but, they could make the classes better or the graduating student better at air management. Maybe they could have a reporting system where you can be reported as an unsafe diver but, I think this would be impossible to make work.

Anyway thanks for all the help!

 

[gypsyjim]

This summer I took a GUE Fundies class with Bob Sherwood. I knew what gas management meant, I thought, and could always come pretty darned close to knowing my pressure at any point in a dive, without checking the gage, which I still do, often, in case I got distracted, or something unexpected might have been impacting my gas. The only time I have sucked a tank nearly dry since my J valves and no SPG days, was while searching for lost gear in shallow water last Feb, and that time it was not because I was not aware, and alert, but because I constantly monitored that gas until I had no choice but end the dive with SOME gas left in the tank!

I was not aware of HOW to actually plan gas management. Had never learned methods to really calculate and plan gas usage, turn times and pressures based on known SAC rates, depths, times, etc, until I took that GUE class with Bob. Actually calculating gas volume in various tanks, and tank configurations, pressures that result from changes in these volumes, depths, times, etc, for two divers was an eye opening experience for every diver in our group, I believe. Certainly was for me!

I do not know at what point this type of training should be included, but I have not seen it in any real depth, prior to the GUE class.

 

[danvolker]

Many years ago I was on a dive boat out of Sharm part of the dive brief the DM gave us was to let him know when one of us reached 100 bar, then we would start our ascent to our safety stop, the max depth was about 25m. I was with a buddy that had been assigned to me because I was on my own. I briefed her about my hand signals and said I was a wee bit anal about air reserves so I would be checking periodically. Well we had a good dive she was a really attentive buddy. We had slipped back a little from the main Dive group and were following the DMs brief. I remember hitting about 100 bar and thinking wow this group has amazing air consumption! So I caught the DMs attention and signaled to him my remaining Air. He then did a check on the groups air and the majority were well bellow the 100 bar he asked them to report in at. This was supposedly a Advanced Open water group of divers. I was a little shocked about the casual attitude of the divers to the DMs brief. I suppose an example of a "trust me resort dive".

Scary.
One issue is the AOW naming convention, for a skill level that is barely able to survive in a large swimming pool by themselves for an hour....modular dive instruction has created lots of cool sounding names for each "skill" module, but the reality is that few of the names have any resemblance to the skill implied.

Also, clearly the DM "should have" been checking on the air of the people in this group....it sounds like the need for hand holding was high, and this guy was not acting responsibly for a large group of Resort Divers......And to be clear, I don't normally think a DM should be having to check everyone's air and hand-holding on a dive---but plenty or Resorts cater to people who actually need this to survive...this goes back to training, as well as the person having a clue as to their abilities...

Regards,
DanV

 

[Ken Kurtis]

I don't want to sound like I'm whining but . . .

Would it be better simply NOT to teach OOA options? And to simply say, "If you run out of air, there's an excellent chance you're going to die, so don't do it." (Or maybe teach OOA options as an advanced skill.)

It may have been inartfully written, but . . .

For those of you who have taken me to task for this sentence, I'd ask that you pause for a second and differentiate between a hypothetical extreme question that's designed to get you too THINK aas opposed to reading it as me saying "This is how we should solve this issue."

The problem is that divers are running out of air - and dying - despite their training or what we tell them. So maybe it's time to re-examine the teaching model and really think about what we're doing, what inadvertent messages we may send, and how we can do things better.

Another way to think about it would be to ask yourself, if you had to choose one, which you consider to be the more important skill: gas management . . . or . . . out-of-air techniques? Then (if you're an instructor) see how much class/pool time you spend on each and decide if the proprotions are correct.

Trite sayings (but perhaps fitting for the topic):

AN OUNCE OF PREVENTATION IS WORTH A POUND OF CURE.

THE DEFINITION OF INSANITY IS DOING THE SAME THING OVER AND OVER AGAIN AND EXPECTING A DIFFERENT RESULT.

- Ken

 

[Peter Guy]

Ken, thanks for starting the thread -- and for reading my prior post and thinking it worthwhile!

We keep dancing around it but, in fact, the basic scuba diving training is:

a. Just fine because so few people get injured or die; OR

b. Terrible because a few people get injured, hurt the environment or die.

Of course it is both -- the vast majority of divers, even beginners, survive and generally enjoy the experience. BUT, there are some number (and who knows really how many -- some 12/year on avg. here in the PNW) who die primarily because their training was lacking -- as in they did not internalize and follow the minimal training they had.

Ken, I don't know how the industry can solve this since the consumer demand is for simpler, and quicker, training. But, I do believe that we, the teachers, could do a better job by focusing on those things which are, in fact, important and ignore those things which, in reality, aren't that relevant. I thought the DAN stats highlighted that we are teaching some of the wrong things -- I still believe that. I wish, under the system I have decided to use, I could spend more time and energy on preventing an accident that is most likely to happen -- going OOA and/or losing buoyancy control.

 

[boulderjohn]

Ken,
I think the stats are being interpreted incorrectly. It is far more likely, that the message here is severely inadequate training for OOA scenarios. And by this, I also mean that if a student can not display a calm state and proceed optimally in a simulated OOA scenario, then they need to be FAILED untill they can accomplish this drill perfectly.

I have another take that requires donning full body armor. Statistics cannot prove or disprove, but I believe that the actual cause of most of those deaths was not out of air, it was panic resulting from inadequate personal ability to deal with being out of air.

Like the posters quoted above, I draw the opposite conclusion. It is not because they have learned through training that being OOA is not a big deal, it is rather because they have not been properly trained enough and so are not equipped to handle it when it happens. In effect, they think it is too big a deal.

Please note DAN's analysis as you quoted it:

For instance, a diver running out-of-air in the open water, panicking, and shooting to the surface might be:

1. Out-of-air (trigger)
2. Panicked ascent (disabling event)
3. Embolism (disabling injury)
4. Drowning (cause of death)​

If the diver had been properly trained for OOA emergencies and believed it was no big deal, there would not have been a panicked ascent to the surface. Even if there had been a panicked ascent to the surface, there would not have been an embolism, for the diver would have known to exhale the entire way and thus avoid it. A panicked diver holding his breath while shooting to the surface is a sign of inadequate training on OOA emergencies, not too much training on OOA emergencies.

...and I have my own theories on why that is true.

 

[boulderjohn]

As I said in the other thread, I have some suspicions about some of those OOA incidents. Another instructor and I recently had experiences (independent of each other) in which students taking the AOW course from us went through their air at an amazingly fast rate during the deep dive, much faster than either of us could have imagined possible. Without our supervision, I am sure each would have been OOA on a real dive. Neither of us had ever seen anything like it. We both told our students that the number one thing they should have learned from the deep dive experience is that they should not be doing deep dives until they get their breathing rates under control.

I was also once in a situation in which I was a single diver on a dive boat with no sign of a potential buddy. My only possibility was an instructor and student doing a deep dive for AOW. The plan was for us to drop down to depth (less than 80 feet), do a couple of routine skills, and then continue with the dive. At the end of the skills, which took only a couple of minutes, the instructor asked the student how much air he had and immediately thumbed the dive when he got the results. I was back on the boat 15 minutes after leaving it.

I think there is a small portion of the population that for some reason go through their air surprisingly quickly when they dive deeper than they are used to. I think even people with more normal breathing rates are surprised by how fast they go through their air at depth. (By the way, the fact that you go through air more quickly at depth is part of the PADI OW course, and there is a question requiring students to calculate the difference on the final exam. I do not believe it is emphasized nearly enough, though.)

For that reason, I disagree with Bob about AOW. I would much rather have students find out about the rate at which they go through air at depth while with an instructor rather than on their own.

 

[AggieDiver]

Ken,

Please don't take it personally when people respond with answers to the question you asked. You intended for people to think about the question even if it was an extreme example, and many have and responded accordingly. I know you were not suggesting that OOA training be stopped altogether, but rightfully wondered if the way we train for it makes it more likely to happen. I would offer an alternative takeaway from the DAN data...that the current training model is working. We train divers intensively (relatively speaking) on the dangers of DCS, and relatively few divers are dying from DCS. So if we apply the same diligence in training divers for gas management and how not to panic in OOA scenarios, we should expect the same level of success in limiting fatalities from OOA scenarios. We see this in industrial safety situations as well...the fatality and serious incident statistics seem to be a leading indicator of where the training should be beefed up and where our safety programs need to focus more attention; but declining incident number statistics can be just as helpful because it tells you where your programs are working and gives you a guide to follow with other topics.

I tend to agree with Boulderjohn in that the OOA situation doesn't usually cause the fatality...it is the inability to deal with it that makes the fatality happen. The OOA causes the incident, the (panic, lack of a buddy, lack of alternate source, overhead env., failure to do a CESA, etc) is what makes the incident result in a fatality. So while it is important to emphasize ways to avoid going OOA, rather than focus too heavily on not getting OOA...we should focus on the things that are killing people...ie. how to make sure you can survive IF you DO get OOA.

 

[spoolin01]

Not being a really smart guy or able to analyse like a college boy I find it hard to see the mindset behind the recommendation that if you run out of air and are still alive that the certifying agency revoke your cert till you get further instructions or that OOA options only be taught in an advanced course (another cash cow for the cert agencies) or that it is detrimental to teach or at least discuss your options for survival if you run out of air since NOT running out of air is probably the most important aspect of diving. You could probably live through most other disasters but not being able to breathe while under water is an absolute no-no. Personally, I think that not enough attention is paid to advising new divers their options if they DO run out of air and that it is foolish to ignore the problem because of some outlandish opinion that is it is better to not teach a diver how to survive if the occassion arises. But that is the mind of the analytical academic at work. Most of them don't live in the real world.

Cutting, but not undeserved. I think these discussions should come with a disclaimer to the reader:

This discussion may have no relevance to your diving needs, may lure you into a seriously skewed take on diving risk, and is likely to needlessly frighten you and distract you from a sober approach to risk assessment and self-preservation.

I assume that the reason DCS is emphasized in OW training, and gas management is given the arguably too-simple treatment it gets, is because for recreational diving DCS is likely to hurt you, quite possibly badly, while indifferent gas management is likely to have very little consequence at all - assuming no panic or unsafe ascent. In other words - dive at rec depths, mind your bottom time, and you'll be OK, particularly if you pay attention to the trigger mark on the SPG. Very simple, and simple is good. Moreover, doesn't air depletion occur with notable warning, giving the rec diver time to surface safely, even if they are remiss about watching the SPG? Compared to DCS, air supply seems much more instinctually manageable at rec depths.

What are the benefits of a more detailed gas management scheme for rec divers? I can see how some will appreciate the education, but how is it a tool they need? My take is that depth is the core parameter to build risk assessment around, gas management but one aspect that becomes more important at depth. Wouldn't it be better to emphasize the rec depth limit and risks of depth in OW training - with detail - and leave the suitable tools for more advanced training? Maybe that's what many are proposing...