Dispelling scubaboard myths (Part 1: It is the instructor not the agency)

[diverintheflesh]

HI Carlos,

I have been diving for (only) almost 3 years. I only completely DM training and got my DM cert 3 months ago. My DM cert is from SDI.

SDI Divemasters are more limited than, for example, PADI DMs in what we are allowed to do. So, I mostly help the instructors by babysitting students when the instructor needs to split the group and have 1 or 2 doing skills while the other wait. And, out of the water, I help with logistics and with making sure the students do things like assemble their scuba unit correctly. Also, I am doing my IDC now, to become an instructor. So, I expect to start giving some of the presentations and demonstrations soon - under direct instructor supervision, of course.

I don't mean to be flippant, but my opinion of the best way to prevent decompression sickness is to always do enough decompression. Peeking under the covers of that statement yields a much longer discussion than I can get into right now. Plus, I don't really feel qualified at this point to say what is the best way to ensure an OW student always in the future does enough decompression (as that is how I interpret your question). I feel like I am still very much on a steep learning curve to understand the meaningful answers to that question.

Awesome. I don't think you're being flippant at all. I didn't hear anything contrary to open and honest communication or answering the question with the experience you have at this point. With that said, your insight into what could lie under those covers is the key to DM'ing and being a good instructor. We must be open to the ideas that we need more education and more information. It is possible that what we've learned could be wrong. As our educational foundation grows, we'll be more knowledgeable, thurough, and be comfortable with what we know, but also what we don't know. To answer my question, more decompression could help lower the risk, so that is a valid method for mitigating risk. But there is at least one way, if not two if we are to be litteral, to prevent DCS. I use this question as bouncing board to help me get an idea as to one's understanding of decompression theory, however, hearing the question is always different from what the other is really asking for...

 

[stuartv]

I have been told that John Chatterton teaches in his classes that "there is only one reason anyone ever gets bent. They didn't do enough decompression."

That definitely rings true to me.

 

[TMHeimer]

I like lectures. I don't care if it has been proven not the most effective teaching/learning method.

Yeah, I'm OK with them too. Simple procedure and you take notes. But I can see why it is not the best method since a majority don't like them. Everybody's different.

 

[diverintheflesh]

I have been told that John Chatterton teaches in his classes that "there is only one reason anyone ever gets bent. They didn't do enough decompression."

That definitely rings true to me.

That could be true, but outside of an umbilical or a saturation diver, we can only bring a finite amount of gas with us... OC or CC... eventually something will run out. and not accounting for staging or luck, decomdecompression theory still has a lot of holes in it... we just don't know why some people get bent and others don't.

 

[Wookie]

I have been told that John Chatterton teaches in his classes that "there is only one reason anyone ever gets bent. They didn't do enough decompression."

That definitely rings true to me.

I would disagree. The only reason people get bent is that they go diving. Doing enough decompression (slow enough ascent, safety stops, however you want to say it) works for some, but it's hard to rehydrate under water. I've seen lots of cases of the bends where someone did plenty of "decompression", but that isn't always the most important contributing factor, in fact, that one is relatively easy to control.

 

[boulderjohn]

There is a lot to be said for standardized teaching methods using what all those NAUI instructors know would work and what didn't.

There's a lot ot be said against it, too.

That was written a while ago, and we have learned a lot about instruction since then. Teaching on the knees was absolutely standard practice then, for example. I it were written yesterday and we standardized on it, then we will be unable to make any improvements in the future.

When I began to realize that teaching skills on the knees was the main problem in scuba instruction, I was able to experiment with different methods, and I eventually completely changed my approach to teaching all skills while still being within standards. I checked every step of the way to make sure it was all OK to do what I was doing, and I was assured it was. When I approached PADI with the article on this different way of instructing, they were a bit skeptical, but they worked with me and published it. Even then, people all over the place insisted that the approach we were advocating was against standards and warned that anyone using that approach would be expelled from PADI for doing that. On ScubaBoard, 3 people particularly kept saying that, probably producing several hundred posts to that effect between them, even after we had direct quotes from PADI saying it was perfectly fine. It was not until PADI released its new standards and publically stated that teaching skills while neutrally buoyant was the PREFERRED approach that this drumbeat of negativism stopped.

If that old style of teaching had been standardized, none of us who collaborated on that article would have been allowed to even experiment with that approach, and we would have been stuck with old methods forever.

 

[stuartv]

I would disagree. The only reason people get bent is that they go diving. Doing enough decompression (slow enough ascent, safety stops, however you want to say it) works for some, but it's hard to rehydrate under water. I've seen lots of cases of the bends where someone did plenty of "decompression", but that isn't always the most important contributing factor, in fact, that one is relatively easy to control.

Perhaps JC should say "the only reason anyone ever gets bent is that they went diving and they didn't do enough decompression"?

The simple answer to why did someone get bent when they did "plenty" of decompression is that what they thought was "plenty" wasn't enough.

Nobody (that I know of) is saying that we KNOW how to figure out how much is "enough" - until after the dive, anyway. "Did get get bent? No? Then you did enough." Figuring out (in advance) how much is "enough" is the "peek under the sheets" that I was referring to earlier.

 

[boulderjohn]

And what is YOUR opinion on the competence of the average current OW grad as compared to the average freshly minted diver that came out of NAUI training in, say, the 70s?

I didn't see the freshly minted diver in the 1970s, so I can't compare.

I believe, though, that in both the 1970s and today, it depended then and depends today dramatically upon the individual instructor--which is the whole point of this thread.

 

[BDSC]

but it's hard to rehydrate under water.

Not sure I understand what you were trying to say with this one.

 

[Wookie]

Not sure I understand what you were trying to say with this one.

Just that I don't think doing long enough stops (which is how I interpret "doing enough decompression") is the only way to avoid DCS. I've been hit a number of times, and only once was it because I didn't do long enough stops. Most often it'd because I was dehydrated.