OP
Triggers of Dive Accidents
- Thread starter Ken Kurtis
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Never having had a former student go OOA to my knowledge, I can of course thump my chest and say I do a great job, but I don't know if it is any better than others.
I do agree with those who say that current instruction is generally not adequate in several areas related to safety and should be revamped.
I do not agree with those who say it would add a lot of time to the course, because I have already added the things I think should be changed and find I am completing the course in about the same amount of time. It doesn't take a whole lot of extra time to talk about gas planning in the classroom, especially if you have prepared handouts. It doesn't take a lot more time to do a lot of other things, either.
In addition, if you look at the PADI confined water standards, in each of CW dives 2-5, students are supposed to have time for fun and practice. During that time they should be engaged in practicing skills, including OOA drills, while they are in different postures, including neutrally buoyant and while swimming. If you have them swimming around the pool, it takes no extra time to have them practice skills as they do it. If you are just working on these skills at the specified moments in the course, you are teaching the course at the bare minimum possible, and not as it is designed.
One of the things I think is wrong is that most people do not realize that last paragraph. The idea that students are supposed to practice all skills during confined water, and do them while neutrally buoyant, was not clear to me, either, until very recently. In recent conversations with PADI, the above information was made very clear to me.
I have also talked about my concerns with the process by which we teach CESA, which I feel is not only not effective but is actually counterproductive. But that's a different story.
I do agree with those who say that current instruction is generally not adequate in several areas related to safety and should be revamped.
I do not agree with those who say it would add a lot of time to the course, because I have already added the things I think should be changed and find I am completing the course in about the same amount of time. It doesn't take a whole lot of extra time to talk about gas planning in the classroom, especially if you have prepared handouts. It doesn't take a lot more time to do a lot of other things, either.
In addition, if you look at the PADI confined water standards, in each of CW dives 2-5, students are supposed to have time for fun and practice. During that time they should be engaged in practicing skills, including OOA drills, while they are in different postures, including neutrally buoyant and while swimming. If you have them swimming around the pool, it takes no extra time to have them practice skills as they do it. If you are just working on these skills at the specified moments in the course, you are teaching the course at the bare minimum possible, and not as it is designed.
One of the things I think is wrong is that most people do not realize that last paragraph. The idea that students are supposed to practice all skills during confined water, and do them while neutrally buoyant, was not clear to me, either, until very recently. In recent conversations with PADI, the above information was made very clear to me.
I have also talked about my concerns with the process by which we teach CESA, which I feel is not only not effective but is actually counterproductive. But that's a different story.
AggieDiver
Contributor
The problem though is how many of that 41% were doing things directly against what they were taught to do that led to the OOA? If a significant majority were doing things they were explicitly taught not to do or things they knew they had not been trained to handle (overhead environments), how will changing the training program change that behavior?
spoolin01
Contributor
spoolin wrote
But it appears your assumption is just flat out wrong -- at least IF the DAN stats are anywhere near accurate.
I admit I don't know much about DCS, why it occurs for example, but I do know that there does appear to be a very significant link between time and depth.And what do we know about the Basic Open Water Diver -- she doesn't (or at least isn't supposed to) go very deep nor can she stay there very long.
If the BOWD stays anywhere near the limits of her training, she'll max out at 60 feet or so and even on air she will have a long time to look around -- PER THE NDLs. But, if she is in the tropics, she'll probably be breathing off an 80 (that's what, 12 L in the rest of the world?) with a SAC of 0.6 (and if male, 0.8). Now IF she has followed her training, she has done the basic calculation (here I'm using the PADI RDP) and found she can stay down for 55 minutes so that is her plan -- afterall, the shop is giving me a tank and shouldn't I be allowed to dive for the whole time? Ooops, at a SAC of 0.6 (which is being very generous for a new diver) she runs out of air at 42 minutes while her boyfriend runs out at 32 minutes.
So tell me, which is more important to plan, your NDL or your Air supply?
For my butt, I'm going with NDL. What if she's just done back to back deep dives or has a bigger tank? I can readily survive ignoring my SPG at rec depths, which is I'm sure proven daily around the world. By contrast, I can't anticipate DCS except by planning, and the consequences of acute failure are worse than OA-under-most-circumstances. Those of even pushing that deco limit are probably not worth risking either, if you plan to dive a lot. Rather than deaths - which are rare in any event, and don't capture morbidity risk - maybe a better set of stats would be frequency of chamber use or O2 administration for suspected or anticipated DCS by those who come within some arbitrary proximity to NDL, compared to that for treatment sought subsequent to surfacing with 0-500 psi left in the tank.
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I forgot about freediving skills, which are perhaps even more important to the prevention of panic than anything I mentioned. I recently took the 3½ day intermediate level Performance Freediving course and it was apparent that every student in the class had a comfort and competence level in the water that was as good as any I have seen. (emphasis on the period)
I think this is actually a really good discussion. I can already see a few places where very minor changes could make a big difference, compared with the class I remember taking. A few minutes of lecture time about gauge checking, and adding the things I mentioned before (swimming up to students and asking for pressure, and scolding them if they don't already know), as well as a brief discussion of the "rock bottom" concept -- maybe not even the calculations, but just the IDEA that you should be carrying enough gas to get TWO people home, might make a difference. Just a change in emphasis, not really a change in content. We spend SO much time on the tables and on DCS, when in fact, DCS from recreational depths (as opposed to AGE) is rarely fatal, although it certainly can be disabling. Why not spend a few more minutes stressing the peril of exhausting your gas supply, and really TEACHING some good habits to prevent it?
OP
Ken Kurtis
Contributor
I understand the point you're making but I think there may be a general misconception that DCS causes more fatalities than OOA.
I just got off the phone with Karl Huggins, Director of the Catalina Hyperbaric Chamber and we discussed this issue. Karl reaffirms that the bends (decompression sickness - DCS) is rarely fatal.
However, he does point out that air embolism can definitely be fatal. An air embolim primarily happens because a diver made a rapid/panicked ascent holding his breath, which can certainly be an outcome if a diver runs out of air.
Karl doesn't have any fatality rate numbers for OOA vs DCS (nor do I) but our general thought is that an OOA situation has far greater potential to result in a fatality (due to air embolism &/or drowning) than does a DCS/bends situation.
- Ken
Have "we" been teaching freediving skills? Free ascents and a self-rescue mind-set? What it feels like to loose a mask in the ocean (not just flood and clear)? Performing swimming tests for acceptance into the class? Just examine some of the questions and responses posted on this board and tell me how effective training has been. How many people that get certified would be in at high risk from an inconvenience like their BC hose falling off?
It is not about rules, it is about panic.
If it will happen, then people should know what it feels like. Let students breath their tank down in the pool. Unfortunately, the extraordinary performance of balanced first stage regulators allows people to suck a tank down to the IP plus bottom pressure until they notice resistance. I sincerely believe an unbalanced first stage is safer for the vast majority of recreational divers, which certainly perform quite well to the 197'/60 meter depth.
WOW!! What a thread. I'm still reading through it all but as an instructor, I do stress gas management. My basic statement is rule of thirds but there is nothing dumber than an OOA emergency and only one person to blame.
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