Teaching contradictions: differing dive training philosophies

[DCBC]

Whoa, whoa, whoa! Misleading vividness here. I teach CESAs and have stated such. I would suggest that you are clouding the question asked of you. Show me evidence, er "solid scientific evidence" that practicing vertical CESAs produces safer divers than having them only practice horizontal CESAs. No obfuscation... stick to the question.

I have not said anything against how CESA is being taught. As you're aware, some agencies don't require this at all for certification (I believe NASE is among these). I did state how I teach it and that's vertically. I believe that this is in the student's best interests if it's done properly, but that's my opinion. I understand why some agencies don't teach it. As you may recall, it was I who posted the paper on why one group of researchers questioned its continued practice. I've also stated that because certification standards have been lowered (and this trend continues) that in a shorter program, is this skill still viable, or should it be discontinued? I also posed the question that in-light of the decrease in Instructor standards (and this trend continues) will the capabilities of the 'Instructor of the future' be high enough to continue CESA instruction?

...Do you have your students kneel? What is your take on that.

I have diver familiarization participants kneel on the bottom. If they decide to commence a diver training program, the kneeling stops on SCUBA.

Here we have more confusion. It's a second dive, but it isn't. It's interesting that they used the word dive rather than dives or descent, isn't it? It's also interesting that they don't mention third, fourth etc dives.

It's not a second dive. It is logged as dive one. Even though more than one ascent/descent has been made, if the TBT is less than the maximum allotted (55 Minutes at 60 FSW), it is a NO decompression dive and is WITHIN the rules set-out by the authority. My students are aware of my profile and I use it as an additional decompression problem that they review during the surface interval. They know my dive conforms to the tables. No "bad example" has been shown.

You've extrapolated the tables to include your kind of diving because it does not specifically exclude them. That's NOT solid scientific evidence but rather putting a spin on a swag. Any self respecting student of decompression will tell you that tables are not solid, but a SWAG (Scientific Wild Arsed Guess). Maybe you should do some research on what constitutes "solid scientific evidence". As of this point, I can say that you're doing it wrong.

You specify that I'm doing it wrong, but don't clarify why. It would appear that you don't have a grip on the rules of the decompression tables at all, or you disregard them (an equally hazardous situation). In any regard, it would appear that you pass on selective practices and not ones that are considered to be best practice within the industry.

...As for being "full" of oneself, you're the one claiming to be an expert on decompression theory, not me. I suppose you have a PHD to back up that claim? Sure, we know by your claims you've participated in some studies, but in what capacity? Were you the leading scientist, a facilitator or just a lab rat? Give us some perspective please. Did those studies include yo-yo divers? I suspect it's just more unsubstantiated extrapolation on your part, but that's just a SWAG at this point.

I've made no assertions based upon my credentials. When you told me "You're missing the real risk of multiple ascents. I would say doing the three dives in such a manner to be excessive and not something the tables were designed to compensate for." I replied "I certainly can't comment on how all decompression tables were designed, but as a member of the DCIEM research team who put together DCIEM's sport diving tables, I don't think I'm missing anything..." I still don't.

In response to your statement, I have an Master of Science in Physiology from the University of Toronto (in-particular, how human physiology can be affected within hypobaric/hyperbaric environments). My capacity at DCIEM was Diving Officer. I was in-charge of DCIEM's hyperbaric facility and its staff and reported to the Deputy-Director. I'm recognized as an expert witness in the fields of recreational and commercial diving by the Supreme Court of Canada, the Supreme Court of the United Kingdom, the Supreme Court of India and the European Court of Justice. I do not consider myself to be a hyperbaric medical expert, nor have I ever suggested that this was the case.

 

[diveprof]

There is a Peter Murray from Key Largo listed as an instructor on the NASE website. According to the NASE website:

"Each level of scuba diving training is consistent with those of other organizations and NASE scuba classes often exceed requirements of other organizations."

One cannot adequately assess the student's mastery of this skill by swimming horizontally underwater. The mechanics are very different as is the impact on the student. Assessing mastery is a requirement. My students clearly understand that this is not a preferred option and that they would have had to make several major mistakes to reach the point where a CESA is necessary. Yet, I prefer that they actually be trained and their mastery of this skill be assessed in the event that it should be required.

This is my last post on this thread. I see it as a waste of time. I encourage all who are interested in this topic to just review the responses, information and observations made thus far and make your own assessment. What I see is that Netdoc is picking bits and pieces of responses to respond to, often ignoring the major question unless called on it and then engaging in hyperbole. Several have commented on his not responding to the question. He states that training in OW CESAs presents a safety issue of the instructor. There is no evidence to support this. In fact, the absense of information from DAN or other scientific bodies or even reports on ScubaBoard under "accidents and incidents" would support that this is NOT a significant issue. The thread topic seemed to change when he was losing traction on the CESA issue and other stuff (kneeling on bottom) seem to suddenly take precedence. My last comment on "kneeling on the bottom" was actually in jest recognizing this change of direction. Actually he decided to change the entire title of the thread to accommodate his change of direction. OK, I've said my piece. Let others decide.

---------- Post added December 13th, 2012 at 02:44 PM ----------

Said this would be my last post, but I wanted to clarify a few points in case they weren't clear. In sentence 3 "Assessing mastery is a requirement" I am referring to my agency requirement. As has been stated there are other agencies do not have this requirement. Netdoc, my comments in the second paragraph were my initial response to what I saw as changing the subject of discussion following my post when so many were challenging your viewpoint. Upon reflection this may have been that you were responding to others at the time. Please accept my apologies if this was not your intention. Though we may agree to disagree on the issue of CESAs, I do applaud and agree with your focus of bouyancy control and staying off the bottom in your training.

 

[The Chairman]

As you're aware, some agencies don't require this at all for certification (I believe NASE is among these).

This is wrong as is your assertion that you "made no assertions" based on your credentials.

This past weekend I attended a wedding, where I got to meet Nick Bird, the Chief Medical Officer for DAN.org. We were talking about people just not getting it, I brought up this very thread. His remarks were that instructors ARE at an increased risk during instruction and that so many vertical CESAs may very well be the culprit. Moreover, he liked the idea of only doing them horizontally and teaching in a manner that does not incorporate other bad habits such as kneeling. I have invited him to this thread and I am sure that if he has time and the inclination that he just might chime in.

 

[Thalassamania]

This is wrong as is your assertion that you "made no assertions" based on your credentials.

This past weekend I attended a wedding, where I got to meet Nick Bird, the Chief Medical Officer for DAN.org. We were talking about people just not getting it, I brought up this very thread. His remarks were that instructors ARE at an increased risk during instruction and that so many vertical CESAs may very well be the culprit. Moreover, he liked the idea of only doing them horizontally and teaching in a manner that does not incorporate other bad habits such as kneeling. I have invited him to this thread and I am sure that if he has time and the inclination that he just might chime in.

This is perhaps the most bizarre appeals to authority logical fallacies that I have ever read. As I noted earlier, I have not seen anything in the literature, or from the agencies, or even the popular diving press, concerning any risk to instructional personnel stemming from conducting CSEAs, beyond ear equalization issues. I rather doubt that Bird would release such potentially explosive information to the public in a private conversation at a social function, so I must conclude that either you misunderstood what he said or he misunderstood your question or statement. I think it is of critical importance for Bird to either separate himself from your claim or to explain, in detail, what data there is to support this hypothesis and why this data has not yet been made available through normal channels.

 

[The Chairman]

why this data has not yet been made available through normal channels.

Apparently, the data is available. Hold on to your horses... I knew you wouldn't believe me, so I asked him to participate and have sent him a link to this thread. Let's hope he shows up. Again, I have thought this made sense, and we'll see if there is actual data to back it up.

 

[Thalassamania]

We're waiting, again I must ask, "what data there is to support this hypothesis and why this data has not yet been made available through normal channels?"

The only paper I know of that addresses anything remotely resembling this question was by Edmonds and was published in the AAUS Dive Computer Workshop Proceedings. As best I can recall, Edmonds had taken a number of divers on rapid deep excursions in a chamber that were "controlled" by an EDGE Dive Computer. The dives themselves were in excess of 150 feet. The dive times were limited by the computer display such that the divers were kept in a no-decompression status (according to the computer) for the entire dive. After a short surface interval, another such dive was made, and another, and another, etc. After a series of such dives were completed (again, as I recall, on the order of 10 dives) a few of the divers exhibited signs of DCS.

 

[DCBC]

...This past weekend I attended a wedding, where I got to meet Nick Bird, the Chief Medical Officer for DAN.org. We were talking about people just not getting it, I brought up this very thread. His remarks were that instructors ARE at an increased risk during instruction and that so many vertical CESAs may very well be the culprit. Moreover, he liked the idea of only doing them horizontally and teaching in a manner that does not incorporate other bad habits such as kneeling.

I for one look forward to Dr. Bird coming onto SB and explaining why the U.S. Navy, DCIEM, NAUI, the World Underwater Federation (CMAS) and the International Marine Contractors Association (IMCA) have had it wrong all these years!!! I'm sure that it will be a revelation to each of these organizations as well!!!!

Failing this however, I'll chalk it up to an individual who will try any tactic to get-out of being proven wrong on his own Website. Pride and vanity can be a bitch...

Through pride we are ever deceiving ourselves. But deep down below the surface of the average conscience a still, small voice says to us, something is out of tune. ”
- C.G. Jung

 

[The Chairman]

I for one look forward to Dr. Bird coming onto SB and explaining why the U.S. Navy, DCIEM, NAUI, the World Underwater Federation (CMAS) and the International Marine Contractors Association (IMCA) have had it wrong all these years!!! I'm sure that it will be a revelation to each of these organizations as well!!!!

The problem is that you only see this in only one dimension. People have been bent following the tables perfectly... even being conservative with them. But, being bent isn't the only possible injury divers and instructors expose themselves to. Our understanding of decompression physiology is a SWAG at best, even after all these years. The researchers never used a set of yo-yo divers to vet the tables with. Your extrapolation to include them flies in the face of diving responsibly and is not covered by any science.

Failing this however, I'll chalk it up to an individual who will try any tactic to get-out of being proven wrong on his own Website. Pride and vanity can be a bitch...

So now you resort to casting sophomoric aspersions? This is simply a strawman at best and an ad hominem at worst. No, it's not as bad as wishing harm to one of my students as you did earlier, but it appears that you are ascribing your motives to me! Talk about someone resorting to "any tactic".

Through pride we are ever deceiving ourselves. But deep down below the surface of the average conscience a still, small voice says to us, something is out of tune. ”
- C.G. Jung

This is a great point and is what I am trying to get you to do: to stop deceiving yourself into thinking that you are above the very things you teach. I sincerely doubt that in real life that you kneel on the bottom or dive like a yo-yo. Why set that example during someone's training? Deep down, you know it's wrong, wrong, wrong. Train like you dive so your students can dive like they've been trained. No confusion. No bad examples. No hypocrisy.

 

[Thalassamania]

Still waiting.

 

[DCBC]

The problem is that you only see this in only one dimension. People have been bent following the tables perfectly... even being conservative with them. But, being bent isn't the only possible injury divers and instructors expose themselves to. Our understanding of decompression physiology is a SWAG at best, even after all these years.

Yes people get bent. As an instructor, the best way of mitigating this is to explain the rules that are provided by the Authority. Not "my rules," but those which have been based upon the science of decompression theory. You discuss the variables and build additional safety into the profile (conservatism).

The researchers never used a set of yo-yo divers to vet the tables with. Your extrapolation to include them flies in the face of diving responsibly and is not covered by any science.

And what do you base this statement on? A guess? How do you think that the decompression rules were developed by the authorities? DCIEM and the U.S. Navy just thought that if the SIT was less than 10 minutes, well... lets just add it to Dive 1 based on nothing??? Do you really think that's how the decompression tables were created???? I was personally involved in multiple descents involving a <10 minute SIT profile from various depths. Numerous other dives were undertaken by Staff in a similar way. Previously thousands of dives have been conducted to establish the parameters of the Tables.

You seem to miss the obvious and make statements indicating that you somehow "know as a matter of fact," when the truth is that you are speculating on something you have no idea. You discount the 10 minute SIT rule, make-up your own rule and teach your students to do likewise. Moreover, you say that those who use the Tables (as they were designed to be used) are setting a bad example. That's just arrogant.