Triggers of Dive Accidents

[Hammerhead]

Phenomenally rare. The equipment today is very reliable. (Wish we could say the same about the divers.) In the 30-or-so fatality cases where I've done equipment analysis for the L.A. County Coroner, we've seen only one case where the equipment factored in, and in that one, the diver basically pulled on the gear so hard he disabled the inflator by pulling it out of the hose (it was easily fixable by re-inserting the inflator into the corrugated hose) and then panicked. FYI, he had 1000psi still in his tank.

Bear in mind, my don't-teach-them-OOA-options is more for hyperbole than a practical solution. And consider this if you're an instructor: Suppose there were no OOA options. How would you change what and how you teach about gas management?

But I really DO think we send the wrong message with the way we teach and while you can easily make arguments for the unlikely events that might necessiate alternatives, it doesn't address the issue that divers are running out of air on a regular basis despite the fact that we tell them over and over again not to.

THAT'S the problem we've got to solve.

- Ken

Whilst I'll agree on the rarity of equipment failure, it does happen, and can happen to anyone.

The one time it's happened when I was involved, the first stage o-ring blew on my buddy's reg at 25m. Knowing that there was a spare reg on the boat (no spare tanks, though) , I passed my octo and turned off his tank. We surfaced, replaced the reg and planned another shorter and shallower dive nearby.

The guy in question was (and is) a PADI Course Director.


Quick edit: - just for the record, the reg in question was less than a year old, well maintained, and the incident occurred in April this year. So it's not a case of old or shoddily looked-after equipment.

 

[billmosel]

I lump this into Gas Management. I know there are many people on this board that preach up and down about Gas Planning. There are even some great articles on this board about how to plan your gas.

But...

After reading those guide, I can't remember any of them really explaining how often your air pressure should be checked underwater. Sure, veteran divers don't need to check their air very often because they know how they breathe. Newer divers don't have a firm grasp on that yet.

Give me a tank with a random amount of air in it. I can attach my gear and enter the water without any gas planning. No matter what the volume of air is in the tank, I can guarantee you that I will make it back to the exit point safely and with some air to spare. Why? I monitor my air while underwater.

If you monitor your air underwater, there is never a reason (short of unexpected equipment failure) that you should ever be surprised by the amount of air left or ever run out of air.

Even most of the text books (from all agencies) gloss over this fact. Sure they mention "check your pressure gauge", but they never go into the frequency of checks.

This is one thing that I try to beat into the heads of my students. If you are monitoring your air, then you should never run out. It is plain and simple. There should never be a point for a new diver that they look down and see "OMG, I am at 500 PSI". Somewhere along the way they should have noted that they were at 2000, 1500, and 1000.

I do teach gas planning, but I spend more time on gas monitoring. I teach they should check their air pressure after any significant event. Gear up - check air. Hit the water - check air. Having problems clearing your ears - check air. Reached our depth - check air. Look at shark - check air. Water in the mask - check air (after clearing). Had to dump some air from the BC - check air. Checked out the seahorse - check air. In class, I want them to check their air each time the successfully complete a skill.

If the student is properly geared and streamlined, it should take mere seconds to check the air pressure. Nothing is being missed on the dive by frequent pressure checks.

Back to the question, most people don't teach any kind of air monitoring. The students are taught that a certain signal from the instructor means report your air pressure, but they are not taught to self monitor their remaining air.

My point exactly!

 

[Ken Kurtis]

If you monitor your air underwater, there is never a reason (short of unexpected equipment failure) that you should ever be surprised by the amount of air left or ever run out of air . . . I do teach gas planning, but I spend more time on gas monitoring . . . Nothing is being missed on the dive by frequent pressure checks.

Excellent points and a great distinction between gas planning and gas monitoring.

I think too often we tend to think of them as the same thing. Gas planning is great but it does you no good unless you monitor your gas during the dive to make sure you're still on the plan.

Like you, I also teach my students that they should be checking their air often enough that they notice 2500, 2000, 1500, 1000, and 500. I tell them that if they ever check and it's been more than 500psi since their last check, they're not checking often enough. I also teach them to dive with the pressure gauge (literally) in their left hand so they'll feel it there and be encouraged to look frequently.

There's no sin in checking your air pressure too often but there can be big problems if you don't check it often enough.

- Ken

 

[milkmood]

I'm sure this video has been posted on these boards before, but it's worth watching. It tells a frightening story of an OOA scenario that absolutely WOULD have ended in 2 fatalities. Not only were the two youngsters OOA at 150', they seemed to be narced as well, which is a guaranteed recipe for death.

YouTube - Diving Accident Potential For A Bad Outcome Bahamas 12/12/08

 

[danvolker]

I'm sure this video has been posted on these boards before, but it's worth watching. It tells a frightening story of an OOA scenario that absolutely WOULD have ended in 2 fatalities. Not only were the two youngsters OOA at 150', they seemed to be narced as well, which is a guaranteed recipe for death.

YouTube - Diving Accident Potential For A Bad Outcome Bahamas 12/12/08

Was that Mount Olympus?
In any event, you did a great job of preventing Darwin from having a big party.

The 2 divers appear to be similar to a type we see vacationing alot...they don't know what they don't know....so they have no fear of depth, or of OOA, or of anything. To me, this was a good reason for the "harrassment style" training of the early seventies with NAUI, or of GUE today
Force the clueless to "experience" OOA, and the probability of them checking their air increases....by this I mean the shut off drills, etc.

Dive sites like Mount Olympus ( if that was the site) which can drop to depths far beyond recreational limits, are poor choices for new or clueless divers....While I do not believe that the boat is normally very responsible for the safety of the divers ( divers should be responsible for their own safety..period), I do not think boats should drop people on a place where the overwhelming probability is that most divers will keep going down til they reach the bottom as deep as 150 or 200 feet down. Places like Mt Olympus are so awe inspiring, and so alluring for you to follow a path down ever deeper, that this deep diving urge is already KNOWN to the boat operator. Whether they think they can mitigate this urge with several good divemasters as depth police, or they only take REAL advanced divers there, they do need to act more responsibly on sites like this.
Anyway, your actions make us all proud! Good job!

Regards,
DanV

 

[milkmood]

I just found the thread where that video was discussed ad nauseam, including discussion and further explanation from the rescuer/videographer.

Very good stuff. The video is a lesson in itself on out of air situations.

Bahamas Close Call Video Discussion

 

[boulderjohn]

Just to return to the issue of teaching CESA, I would like to point out that 10 days have passed since I made this post.

It was a response to String's familiar reference to CESA as "bolt and pray" and his desire that it not be taught to OW students. It is not necessary to read the whole thing--here are the parts I would like to highlight now.

You have been using the term "bolt and pray" to describe this in threads for years, but I have also noted that when people challenge your assumptions and ask questions, you disappear from the thread without replying and don't mention the topic for a few months. So here are some questions.

[Here I asked some questions, questions I have put to him in other threads over the years without getting a response.]

I look forward to your responses.

I would just like to note that in the 10 days since I posted that thread, he has disappeared from the thread and not responded to the questions.

 

[TSandM]

Well, I just want to report that, during the academic portion of last night's OW class, after discussing the CESA and HOW it is done -- I broke in and initiated a short discussion of being out of gas, and how it is, apart from some really vanishingly unlikely equipment malfunctions, an utterly inexcusable thing to have happen to a diver. So this thread changed our practices as instructors; thank you, Ken.

 

[eponym]

[snip] If you are monitoring your air, then you should never run out. It is plain and simple. There should never be a point for a new diver that they look down and see "OMG, I am at 500 PSI". Somewhere along the way they should have noted that they were at 2000, 1500, and 1000.

I do teach gas planning, but I spend more time on gas monitoring. I teach they should check their air pressure after any significant event. Gear up--check air. Hit the water--check air. Having problems clearing your ears--check air. Reached our depth--check air. Look at shark-- check air. Water in the mask--check air (after clearing). Had to dump some air from the BC--check air. Checked out the seahorse--check air. In class, I want them to check their air each time they successfully complete a skill.

[snip]

Back to the question, most people don't teach any kind of air monitoring. The students are taught that a certain signal from the instructor means report your air pressure, but they are not taught to self-monitor their remaining air.

Like TS&M, I've found something in this discussion that changes how I will teach. I like the concept of "check your air after each drill" in the pool and I plan to use it. At the moment my only course is an Assistant Instructor course but I'll be asking no less of them and perhaps that will make a difference down the line when they start teaching.

Thanks for the advice,
Bryan

 

[flots am]

Well, I just want to report that, during the academic portion of last night's OW class, after discussing the CESA and HOW it is done -- I broke in and initiated a short discussion of being out of gas, and how it is, apart from some really vanishingly unlikely equipment malfunctions, an utterly inexcusable thing to have happen to a diver. So this thread changed our practices as instructors; thank you, Ken.

I start off teaching air sharing with the phrase "Pretend you were really, really dumb and ran out of air"

ESA/EBA start off with "Pretend you were astonishingly, amazingly stupid, ran out of air and lost your buddy".

It seems to get their attention.

flots.