Teaching contradictions: differing dive training philosophies

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It has been long accepted in sports training that the best training for any activity is the activity itself. Whether a horizontal is good enough I do not pretend to know, but I do believe that the best way to train for a vertical CESA is to do a vertical CESA. That would make it superior in my book.

Or is scuba that fundamentally different from other sports or activities that a seperate study is actually required?

I think there are a lot of activities where training situations are simulated. When doing CPR training, it is done on a dummy, or pretending to do compressions on a real person without actually compressing. There is obviously an inherent danger to doing actual compressions on a real person (who doesn't need it). However, what we strive for is to make the simulation as close to the real thing as possible while maintaining a reasonably safe situation.

I don't think anyone has argued that vertical CESAs are unsafe (if ensuring exhalation), just that student shouldn't be doing bounce dives. However, since vertical CESAs are slightly different that horizontal (managing expanding gas), I think vertical CESAs are the way to go. I don't think it is unreasonable to explain to students that doing these up and down dives is a really bad thing to do (and why), but for the purpose of education, they are going to be done.

It seems to me that a student that had only done horizontal CESAs, would likely forget to vent their BC (or worse, vent too much) if they had to do a CESA in real situation. However, I have no evidence to back this up....pure speculation.
 
When I brought that up earlier, Pete said there is no need to supervise students as closely as we do during the dives,
Yeah, I don't believe this at all. My #1 job as an instructor is to supervise students and insure that they do no harm to themselves, others or the environment (in that order). That being said, when my students are in complete control of their trim and buoyancy, then this becomes an incredibly easy job. I find that some instructors feel that the only way to control their students is to plant them on the bottom. This denies the student valuable time to assimilate good neutral buoyancy habits and makes the job of getting them to stay off the bottom all that much harder. The best way for the instructor to control their students is to teach them how to control themselves. Then, all you need to do is to supervise rather than do the dive for them.

As a caveat, I see trim and buoyancy as being the foundational skills. All other skills are built onto this foundation. That doesn't make them less important, it just means that they depend on being trim and neutral in order to be truly mastered.
 
It goes well beyond that. For a representative of DAN to come on a forum like this and declare that the procedures used by almost every agency are dangerous and should be stopped, he would have to know what a tidal wave that would cause in the industry, and he would have to have some pretty serious research to support it...

That's why I doubt that there was anyone who read Pete's post actually believed what he was saying (perhaps not even him). So much for showing a "bad example" and projecting a professional attitude.
 
I think there are a lot of activities where training situations are simulated.
As a long time coach certified in several sports by national agencies, I can describe the two most important concepts in teaching a sport, concepts that apply well to scuba instruction. The first is to make the activity game-like--avoid teaching players to do something that is different from what is done in a game. The second is to maximize the repetitions in order to maximize the skill learning. The problem is that these two concepts often conflict. The most game-like thing you can do is to play the game, but that will minimize repetitions--a baseball player can go a whole game without touching a ball. Maximum repetition drills are often very much not game-like. A good coach has to find the best balance, the activity that compromises each ideal the least.

To give an example, you will often see soccer teams performing the worst possible instructional exercise because it maximizes repetitions. Two players face each other and pass a ball back and forth. As they do that, they learn to stare at the ball as it comes to them rather than look away to see what they need to do once they get the ball. They learn to wait for the ball to come to them rather than come to the ball to beat an opponent. They learn to stop the ball right next to them rather than touch it to a space away from an opponent. They learn to pass the ball directly back the way it came, rather than quickly redirect it to another player. They learn to pass it directly to a standing player, rather than to a space away from a moving player so that the player can get it in a free location. Playing a full-sided game teaches the skill better, but it minimizes repetitions. A good compromise is to play a 3 v. 3 game of keep away. It is not ideal for either goal, but it is much better than the more extreme alternatives.

Scuba skill work, particularly CESA instruction, is much the same. In the pool, we focus on the skill work, maximizing repetitions until the student shows mastery. Much of that is in conditions that are not dive like. We can improve that by refusing to put students on their knees, but it is not as good as an OW situation. The horizontal CESA is an example of a situation in which we do our best to make it game-like, but our limitations due to pool depth are such that the effort is counterproductive, like the soccer passing drill mentioned above. That's why we do it vertically in the OW dives, to try to get it into more of a game-like setting.
I don't think anyone has argued that vertical CESAs are unsafe (if ensuring exhalation), just that student shouldn't be doing bounce dives.
Actually, Pete has said that repeatedly. He has said that repeated CESA training is harmful to the instructor. He has been challenged to provide research indicating that his unusual claim is true. He has not done so, and has instead demanded that others show evidence that it is not true.

---------- Post added December 19th, 2012 at 09:37 AM ----------

Yeah, I don't believe this at all. My #1 job as an instructor is to supervise students and insure that they do no harm to themselves, others or the environment (in that order). That being said, when my students are in complete control of their trim and buoyancy, then this becomes an incredibly easy job. I find that some instructors feel that the only way to control their students is to plant them on the bottom. This denies the student valuable time to assimilate good neutral buoyancy habits and makes the job of getting them to stay off the bottom all that much harder. The best way for the instructor to control their students is to teach them how to control themselves. Then, all you need to do is to supervise rather than do the dive for them.

As a caveat, I see trim and buoyancy as being the foundational skills. All other skills are built onto this foundation. That doesn't make them less important, it just means that they depend on being trim and neutral in order to be truly mastered.

Once again, we are misdirecting the response. It is not about kneeling.

Let's take the example I used when you responded along these lines--the alternate air ascent.

I assume from what you described that you you can manage a group of divers doing an alternate air ascent without ascending with each buddy pair because you can see each pair clearly at all times throughout the exercise regardless of where you are. A single instructor in a poor visibility scenario, such as we see using a platform in a quarry, must ascend with each buddy pair. Not only that, the instructor cannot leave other buddy pairs unattended at depth while ascending with another pair. Not only that, the instructor cannot leave a buddy team unattended at the surface while working with another buddy team at depth. It isn't easy.
 
I don't think anyone has argued that vertical CESAs are unsafe (if ensuring exhalation), just that student shouldn't be doing bounce dives. However, since vertical CESAs are slightly different that horizontal (managing expanding gas), I think vertical CESAs are the way to go. I don't think it is unreasonable to explain to students that doing these up and down dives is a really bad thing to do (and why), but for the purpose of education, they are going to be done.

In many pool sessions, divers do yo-yo dives all the time during training. I have yet to meet any Instructor who tells them to get out of the water for a surface interval after one ascent... Although our bodies are absorbing Nitrogen in the pool, we think that it doesn't matter because we aren't deep enough and in a swimming pool. As far as the decompression tables are concerned, pressure is pressure. Are we showing a "bad example" to our students in the way in-which we conduct a pool session? Of course not; that would be a ridiculous assumption.

If we teach by the tables, we should apply them as they were intended. If you complete a dive (descent/ascent), then go back down, you're still "on the clock." It's all the same dive and you add this to the last dive (regardless of how many repetitions that is). If you are following the Tables, no "bad example" is being demonstrated. I'm not aware of one case of DCS that has been attributed to "bubble pumping" in less than 60 FSW. So before anyone starts saying that yo-yo dives break the decompression rules and is "bad practice," look again. Anyone who doubts this, please reference some document that suggests that this is the case.

Steve Goble at the Adelaide Hyperbaric Unit, Royal Adelaide Hospital, Australia has done extensive research into Shallow Water Decompression Sickness (SWDCS). He has suggested the following 'risk factors' that may increase risk.


  • depth (generally, the deeper the dive, the greater the risk)
  • poor physical condition (obesity, age)
  • heavy physical exertion before, during or after a dive
  • alcohol or some drugs (taken before or after a dive)
  • previous incidences of decompression illness
  • multiple ascent diving
  • multiple dives over multiple days
  • prolonged dive times
  • cold conditions
  • prolonged hot showers after a dive
  • preexisting health condition.

Most DCS cases that I've read attribute excessive ascent rate as the key factor responsible. Because of this, a verticle CESA is necessary to evaluate a students ascent rate in an emergency. 'Mastery' of CESA cannot be evaluated in any other manner. In-addition, poor physical condition, work, cold and preexisting health conditions are recognized by the commercial sector internationally to be major risk factors for DCS. Multiple deep ascents are theorized to be a factor, but as no case of DCS has been attributed to this, it has been ruled out by the international commercial diving sector, the U.S., UK and Canadian militaries.

One other point that I'd like to make. We are dealing with Divers who are taking there initial program in SCUBA instruction. At least I don't go into tissue half-times, bubble nucleation, or steady state isobaric counter-diffusion with my openwater class. We have to keep in-mind the level of training that they are doing and the maximum depths which they attain. I'll continue to teach what's in their textbook. I wasn't aware that 'Bubble Pumping" was included in any Agencies student text. Perhaps this discussion should be put into perspective. We should teach what we should teach (and supplement the training as appropriate and allowed by the certification Agency). Not to interject theories that are shaky at best.
 
But seriously, what we were discussing was DCS issues with accent training, not ear problems which I (perhaps over-judgementally) chalk up to bad judgement or insufficient skill.

As usual, thanks for your input. IT means a lot.

---------- Post added December 20th, 2012 at 04:41 AM ----------

Roger, do you think that you're showing a "Bad Example" to your students? Are you breaking any rules, or otherwise diving dangerously by doing multiple CESAs during a check-out dive, or are your ears the only complaint? Please explain why you feel the way you do.

---------- Post added December 19th, 2012 at 06:54 AM ----------


QUOTE]
I am not so concerned about DCS risks when doing CESA since it is both in compliance with the tables and my computer. My ears are the only complaint.

Cheers,
Roger
 
It goes well beyond that. For a representative of DAN to come on a forum like this and declare that the procedures used by almost every agency are dangerous and should be stopped, he would have to know what a tidal wave that would cause in the industry, and he would have to have some pretty serious research to support it. That supporting research would have to be in the form of a top secret study soon to be released, since no one else seems to know about it.
I'm sorry John, I don't buy that. Is he a responsible physician and scientist or simply a creature of the industry following the party line? Or perhaps (what I find most likely) Pete had a cocktail party conversation with him that, in point of fact, did not really actually address the dozen instructors implied to be suffering from a medical/scientific (DCS) issue that Pete started off with that has now been shifted to a list of, perhaps, seven instructors who hurt their ears with too much up and down, something that I'd be inclined to list as failures in technique and/or judgement.
 
What a great pic from Facebook:
46471_4060145862571_1847339520_n.jpg
 
What a great pic from Facebook:
46471_4060145862571_1847339520_n.jpg


Funny... I don't see his feet, knees or butt touching bottom. Do you?
 
Yup, fins are on the bottom.
 
https://www.shearwater.com/products/peregrine/

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