Rote Learning vs. Understanding Concepts

[Web Monkey]

My dive buddy recently asked me the best way to hold the console over the 1st stage when opening the valve. My attempt to explain got the sore retort, "I don't have time for a long explanation, just tell me what to do!" I was, however, able to prevail enough to get her to listen to what's going on when you open the valve.

I was taught that pressure gauges have been known to explode when pressurized, so you should make sure that the face of the gauge is pointing in a safe direction when you open the valve. Apparently, her O/W instructor teaches students to hold the pressure gauge face down over the top of the 1st stage reg when opening the valve. Now, that can have the effect of pointing the gauge in a "safe" direction, or it can mean that you'll blow the shrapnel into your hand instead of your face. Or, in

Knowing "why" is nice, but for at least some things, it's important to do them the right way even if you don't know.

Just for an example, my OW instructor made a big point of making sure that we kept out mask on, reg in and fins on our wrist when getting back onto the boat. He never mentioned why, but was insistent about it, and that's the way we learned it.

For the next hundred dives or so, I just did it without even considering why. When the DM would try to take my fins, I'd keep them. When everybody else was climbing the ladder with no reg and no mask, I had mine on. Then one day I was almost to the top of the ladder and a huge wave came by, picked the stern of the boat up like Styrofoam and slammed it back down hard. I got knocked right off the ladder and back into the ocean. It took a few seconds to figure out what happened and which way was "up", then I realized that I was still breathing, still had my mask on and still had my fins.

If I had handed up my fins and mask and wasn't using my reg, an annoyance could easily have turned into an emergency.

While it would have been nice to know "why" it was taught that way, it really wasn't important. What was important is doing the skill the way it was taught. "Why" came later.

Terry

 

[TSandM]

The problem with absorbing a procedure without understanding why that procedure is prescribed is that you will not recognize a situation where that procedure does not pertain, or may even be hazardous.

The first thing that comes to mind is the safety stop. I am always astonished at the number of people who would execute a safety stop on a dive that's well within recreational limits, when they were escorting a diver who is out of gas and sharing their supply. If you understand some decompression theory (and some history, thank you Thalassamania) then you know what a safety stop is, why it was prescribed, and most important, when it can be skipped. Otherwise, you may put yourself and your out of gas buddy at increased risk by insisting on something which is not required.

Turning a reg on fast may wear the seat on your first stage more quickly. Or, if it's an O2 reg, it may cause a fire. In one case, it's something which is nice to do but not disastrous if omitted; in the other, it can be a major problem.

I like to know why. Knowing why helps me be observant where laziness would lead me to be sloppy, and conversely, helps me know when bending or breaking rules is actually precisely the right thing to do.

I tend to believe that most people can and should be taught why, even if they don't retain it. Although my ER experience has also taught me that there are some people where you should congratulate yourself if you ever succeed in establishing the bare protocol, let alone any of the thought behind it.

 

[MauiScubaSteve]

First off, the bell housing covers the clutch assembly or hydraulic convertor

Like I said "(slim)"

 

[JeffT]

Always point the pressure gauge in a direction that will be the least traumatic in case of failure. Try depressing the Low Pressure Inflater (LPI) button while slowly opening the valve. This will partially inflate the BCD which you will need for entry anyway.

That said, I agree the chance of a pressure gauge failure resulting in injury is slim. About as slim as a piston going through the engine block, hovering motionless, making a 90 degree right turn, then proceeding through the bell housing of the clutch assembly, proceeding through a Kennedy, and then hitting you.

 

[MXGratefulDiver]

Then in Rescue I was taught also to hold the purge button on either 2nd stage so the gas "has somewhere to go".

I don't think that's the reason for holding the purge button. First off, the whole "exploding SPG" notion is a relic of a bygone era, and a false argument. Has anyone reading this ever ... in, say, the past 20 years ... seen an SPG explode? I know I haven't.

But the reason to hold the purge button while slowly turning on the regulator is to save wear and tear on your first stage. When you open the valve, the pressure causes a soft metal-composite "seat" to seal itself against a part of your reg known as a "knife-edge". Holding the purge button while opening the valve reduces the pressure at which these two parts come together. The seat is a replaceable part, and gets replaced whenever your first stage is serviced ... but the knife edge is part of the first stage assembly and isn't replaceable. Damage it and your first stage becomes a nice paper weight. So you purge as you open to minimize the impact ... reducing the risk of wear or damage ... since the reg probably cost you a pretty penny and you want it to last you a long while.

... Bob (Grateful Diver)

 

[redacted]

I agree that knowledge and understanding are much more useful than rote memorization - as long as the knowledge and understanding are correct. At one time the world was flat.

As far as the SPG example goes, all of my SPGs have a built in failure point in the case should the bourdon (sp?) tube fail to contain the HP. On most of them, it is a small rubber plug in the back of the SPG but on one, the plug is on the top. I have never seen or heard of one failing in that mode. I watch the SPG as I turn on the gas.

 

[Peter Guy]

Sam -- in my very limited experience, it is probably best to just give the bullet point -- and then later, at an appropriate time get into the "why" of the action. This, btw, is doubly true if the person to whom you are responding just happens to be in a "special relationship" with you (as I suspect is the case here). IF my suspicion is correct, the ONLY proper response is "Yes dear."

 

[Dr Neil]

Good balanced instruction provides both theory and repetition. Yes one should know the reason and theory behind what is being taught, but the depth and complexity doesn't have to come all at once. If your 6-year old child asks you "where do babies come from?" the prudent parent doesn't go into a detailed and graphic explanation.

Many OW skills should be taught and reviewed until the skill become reflexive. (A classic example is blowing a thin stream of bubbles when you take your regulator out of your mouth.)

Although the chances of a SPG exploding when initially pressurized are statistically slim, the simple act of turning it away usually leads one to immediately check the air pressure once it has been pressurized.

 

[MXGratefulDiver]

Sam -- in my very limited experience, it is probably best to just give the bullet point -- and then later, at an appropriate time get into the "why" of the action. This, btw, is doubly true if the person to whom you are responding just happens to be in a "special relationship" with you (as I suspect is the case here). IF my suspicion is correct, the ONLY proper response is "Yes dear."

... and you plan to learn this response ... when? ...

... Bob (Grateful Diver)

 

[Teamcasa]

I too am a need to understand the context guy.

I'm sure that many of the myths, misconceptions and old wise tales may have had some value in the past but many just no longer apply.

But one thing I have also learned is that no matter the facts, convincing people otherwise is many times fruitless. Just try telling a guy that lowering his tailgate does not get him better mileage.