Fatalities statistics: what kills people the most in scuba diving?

[InTheDrink]

Ken, why are you disregarding failure modes for OOG? That seems like a leap to me if you're looking at cutting off the source of the issue. O-rings do, will and have failed.

The % may be small but must be accounted for especially if you think training for OOG is the wrong direction.

 

[Ken Kurtis]

One thing you might now take into account is that not everyone thinks of out-of-air as an emergency . . . So when I got to the bottom to photograph the diver dredging for clams for our survey, I ran out of air. I buddy breathed with him for about five minutes, until I got the photos I wanted, then surfaced from about 44 feet. I did not consider it an emergency, nor did anyone else . .

I think that's a potentially dangerous mindset. I always ask my professional-level people to reverse-engineer their scenarios and, if something goes horribly wrong, what would people be pointing at and say "What were they thinking?" In your example, IF the buddy-breathing didn't go right (your buddy turned suddenly and accidentally yanked the reg out of your mouth) or IF you free-ascended (no sense in making TWO people come to the surface earlier) and embolised, or IF you couldn't orally inflate your BC at the surface and had no air to do so with an LP inflator, what would the accident analyis point to?

"Emergency" does not equal "panic". It simply means a situation you need to deal with immediately. Why were your pictures more important than that? More to the point, if something HAD gone wrong, were those pictures worth dying for?

---------- Post added February 17th, 2013 at 06:22 AM ----------

Ken, why are you disregarding failure modes for OOG? That seems like a leap to me if you're looking at cutting off the source of the issue. O-rings do, will and have failed.

Not ignoring it. Simply saying that in the 947 fatalties dissected by DAN over a 10-year period, there was not one incidence (that I recall top of my head) of equipment failure causing OOG. I'm not saying it doesn't happen. But if it does and it's a problem that's life-threatening, why doesn't it show up in the data? I think there are some things that we in the diving community accept as true that are really, when you drill down into the facts, nothing more than Urban Legend.

 

[openmindOW]

. . . DAN studied 947 people died. Of those, we have complete information on 350. Of those . . . 144 of them (41%) ran out of air and died. Had they NOT run out of air, they would not have died (on that dive).

Forgive the possible ignorance of this question, please. I haven't read the DAN report.

Do we know that the 144 divers would have lived if they had not run out of air? In other words, do we know that the air loss was the cause of the fatality?

For example, a diver could have a heart attack and die. Is it possible for his cylinder(s) to drain by the time his by the time his body is recovered? In such a case, might this diver be listed as a OOA diver who died due to air loss?

 

[Ken Kurtis]

Do we know that the 144 divers would have lived if they had not run out of air? In other words, do we know that the air loss was the cause of the fatality?

I think the short answer is "Yes." Although you can certainly make the argument that you can't really "know" what would have happened had something else not happened, they ran out of air on a dive and subsequently died. At some point, you can start to try to parse this too much and too finely to the point that you don't see the elephant in the room.

 

[TSandM]

I have been out of air once in over a thousand dives, and it was a freeflow that did it. Of course, I didn't die, so it didn't show up in the statistics.

 

[Rich Keller]

Amongst experienced divers I have always thought that the biggest killer is panic. "In an emergency it is the poorest learned skills that are forgotten first". It is remarkable how many people have drowned when they still had ample breathable gas - due to panic, they just "gave up".

I agree, for me the first rule of diving is "If you panic you die". The other thing I believe is that a lot of times it is a couple of seemingly unrelated problems happening at the same time that can cause a serious problem. Most divers understand and train for the big problems but a couple of small problems that many may not train for happening together can cause confusion followed by panic.

---------- Post added February 17th, 2013 at 11:13 AM ----------

I agree that if you didn't know what you were looking for, you could skip by it. This was part of the presentation (and given in greater detail) made by Dick Vann that's summarized starting on page 73. In his presentation, he had slides (and I took copious notes) indicating that of the 947 cases they studied over ten years, they identified the trigger in 350 of those cases. And of those 350, the trigger was out-of-air in 144 of the caes (41%).

Was there any breakdown of what type of dives they were doing?

 

[Hatul]

There's an equipment angle to the out of air issue. I believe you're more likely to neglect to check your SPG if it's clipped away from your depth indicator, especially for less active and inexperienced divers. The tank pressure should be close to the depth and other computer displays, so when you check your depth you can't help but glance at your SPG. This implies either a console or an AI computer. Even in the car dash, where running out of gas is not life threatening, the gas gauge is not under the dash, but easily visible when you glance at your speed.

Another safety advantage of air integration, is the real-time calculation of remaining bottom time to allow safe ascent without running out of air. It's easy for a diver to overestimate the remaining air time on a deep dive.

 

[dumpsterDiver]

I think that's a potentially dangerous mindset. I always ask my professional-level people to reverse-engineer their scenarios and, if something goes horribly wrong, what would people be pointing at and say "What were they thinking?" In your example, IF the buddy-breathing didn't go right (your buddy turned suddenly and accidentally yanked the reg out of your mouth) or IF you free-ascended (no sense in making TWO people come to the surface earlier) and embolised, or IF you couldn't orally inflate your BC at the surface and had no air to do so with an LP inflator, what would the accident analyis point to?

"Emergency" does not equal "panic". It simply means a situation you need to deal with immediately. Why were your pictures more important than that? More to the point, if something HAD gone wrong, were those pictures worth dying for?

---------- Post added February 17th, 2013 at 06:22 AM ----------




Not ignoring it. Simply saying that in the 947 fatalties dissected by DAN over a 10-year period, there was not one incidence (that I recall top of my head) of equipment failure causing OOG. I'm not saying it doesn't happen. But if it does and it's a problem that's life-threatening, why doesn't it show up in the data? I think there are some things that we in the diving community accept as true that are really, when you drill down into the facts, nothing more than Urban Legend.

The guy can swim 50 meters underwater (now as a senior citizen) and you are asking him what he would have done, dozens of years ago, if the regulator was pulled from his mouth? LOL they were buddy breathing.. the reg IS out of his mouth half the time... and how would he inflate his BC if there was no air in tank? A similarly silly question. It was 44 feet deep!


However, I do agree with you that OOG is something that is dangerous for most people and avoidance of it, would make diving a lot safer.

Also, FWIW.. I witnessed a scuba failure that left a diver with no air. His second stage hose exploded, he had no octopous. I didn't offer him any air, in fact I jumped on his back and shut his tank off, before I released him and allowed him to swim to the surface... Of course the depth was only 20 feet.. As i think back, this same guy ran OOA on me at 90 feet too and I had no octopus and he was signaling for air, and i never gave him the reg, I just grabbed him and swam up, I figured he would take my reg, if he REALLY needed it..

 

[InTheDrink]

The guy can swim 50 meters underwater (now as a senior citizen) and you are asking him what he would have done, dozens of years ago, if the regulator was pulled from his mouth? LOL they were buddy breathing.. the reg IS out of his mouth half the time... and how would he inflate his BC if there was no air in tank? A similarly silly question. It was 44 feet deep!


However, I do agree with you that OOG is something that is dangerous for most people and avoidance of it, would make diving a lot safer.

Also, FWIW.. I witnessed a scuba failure that left a diver with no air. His second stage hose exploded, he had no octopous. I didn't offer him any air, in fact I jumped on his back and shut his tank off, before I released him and allowed him to swim to the surface... Of course the depth was only 20 feet.. As i think back, this same guy ran OOA on me at 90 feet too and I had no octopus and he was signaling for air, and i never gave him the reg, I just grabbed him and swam up, I figured he would take my reg, if he REALLY needed it..

I'm NEVER diving with you ya mean bastard!

 

[John C. Ratliff]

The guy can swim 50 meters underwater (now as a senior citizen) and you are asking him what he would have done, dozens of years ago, if the regulator was pulled from his mouth? LOL they were buddy breathing.. the reg IS out of his mouth half the time... and how would he inflate his BC if there was no air in tank? A similarly silly question. It was 44 feet deep!


However, I do agree with you that OOG is something that is dangerous for most people and avoidance of it, would make diving a lot safer.

Also, FWIW.. I witnessed a scuba failure that left a diver with no air. His second stage hose exploded, he had no octopous. I didn't offer him any air, in fact I jumped on his back and shut his tank off, before I released him and allowed him to swim to the surface... Of course the depth was only 20 feet.. As i think back, this same guy ran OOA on me at 90 feet too and I had no octopus and he was signaling for air, and i never gave him the reg, I just grabbed him and swam up, I figured he would take my reg, if he REALLY needed it..

Dumpsterdiver,

Thanks for the enjoyable post. We were buddy breathing, but I would take two breaths, give back the regulator then back off a few feet for a photo and come back in about 30 seconds. I did this for about five minutes, so the potential for the regulator being pulled out of my mouth was pretty small. I am going to try finding the negatives to see what the photos look like; I may still have them. When I finished, I'm pretty sure that I simply did a free ascent along either the anchor line or the dredge's buoy line to the surface. Concerning inflating the BC, I had two. One was a CO2-operated life vest, and one was a very unique BC built into the back of my wet suit by Bill Herder of Deep Sea Bill's in Newport, Oregon (he has since passed). The back-mounted BC could be orally inflated, as could the life vest. But had this turned into an emergency situation, I would have dumped my 18 pound weight belt, which I did not (I've only done that once, but that's another story).

Now, this thread has been moved into the Basic Scuba discussion, so I must issue a disclaimer--I was not a basic scuba diver. I was a NAUI Instructor (#2710), but also had gone through the U.S. Navy School for Underwater Swimmers and the U.S. Air Force Pararescue Transition School and had been an active PJ (Pararescueman) for about 8 years at that time. Training time for these schools during the Vietnam War was just over a year. During my active duty time, I served in Okinawa, Korea, Bermuda, Florida and Vietnam. I was on the Apollo 13 recovery team, and was trained in parascuba and Apollo floatation collar attachment techniques for rescue of the Apollo; we were responsible for the first minute of Apollo 13's flight--if something had gone wrong then, it was ours (it did not, and ultimately the U.S. Navy got Apollo 13 after days of getting to the moon and back). What I did on that ODFW dive for the photography was well within my capabilities, then and now. After all, we don't stop putting a floatation collar on an Apollo capsule if your regulator was torn off your tank during the parachute jump to the capsule--we make due with what we have, and count on our training, conditioning tools (scuba, knife, life raft, etc.) and experience to see us through.

This morning after church I went to the pool and jumped in with my scuba (a double hose Healthways SCUBA regulator) to do three ditch and recoveries. I was in the deep end of the 18 foot deep pool, and for the first I simply took off the unit, took a deep breath, and swam underwater to the shallow area diagonally across the pool, exhaling all the way. This I easily accomplished. After recovering the unit, I did not put it on, but rather turned off the air after inhaling, exhaled and tried to inhale (of coures, no air). So I put the unit down and repeated the process, swimming diagonally across the pool. This is approximately 25 yards. I was exhaling slightly the whole way, and made it to the "surface" without incident. The third time, I got to the scuba (swimming the 25 yards to get there again), and waited until my respirations were back to normal, then I turned off the air, but this time rather than simply exhaling, I exhaled thoroughly to get to my residual volume (we usually have a reserve expiratory volume, and that's what I was using the second time). This time, while swimming underwater I kept my mouth open, but did not exhale (not much there) until I started climbing out of the 18 foot depth--and yes, there was some to exhale at that point. It was a push, but again I made it to the "surface" 75 feet away. This was without the volume that would have been there had I actually started up from 75 feet depth. One of you made the comment that I probably could not have made it if I had exhaled in a previous post--I can!

Now, I also agree that we should avoid OOA situations. But my feeling is that with sufficient watersmanship (or waterswomanship ) OOA by itself should not induce panic. It can easily be coped with in normal sport diving environments (defined is less that 120 feet depth, with no "overhead" environments, including no decompression obligations).

SeaRat

---------- Post added February 17th, 2013 at 07:20 PM ----------

I am curious as to why this thread was moved from the Accidents and Incidents forum to the Basic Scuba forum?

John