Learned Wrong...

[MXGratefulDiver]

Not something I learned wrong, but something I saw taught wrong....

An AI was teaching some OW students about SAC rates. On the previous dive he had them calculate their resting SAC rates (sitting on the bottom, resting for 1 minute). He was now during their SI having them calculate their required gas for the next dive based on those resting SAC rates. :shocked2: To ignore rock bottom is one thing, but to instruct OW students who do not know any better to vastly underestimate gas consumption, and then plan dives on that faulty information (given that most of us do not own scooters and must actually "fin" to get anywhere on a dive) was ridiculously stupid and dangerous (not necessarily during the class, but for future dives conducted now with no safety margins). Not that I'm advocating it, but better to not teach SAC's at all and leave it at surface with 500psi.

I'll give the dude props for teaching it at all ... most instructors don't. I've met many who think it's not needed ... that telling someone to watch their gauge and abort the dive at 500 psi is sufficient (sure it is ... that's why OOA is so common). But it's far easier to fill in the gaps if you know a certain type of knowledge exists.

I teach that SAC rate is not a number ... it's a range, and that your actual usage depends on a lot of variables such as diving conditions, swimming speed, and several other factors that can vary day to day, dive to dive. I liken it to the MPG on your car. You can use an "ideal" number as a baseline, but then you have to factor in what's going to affect it if you want to know how far you can make it on a tank of gas.

... Bob (Grateful Diver)

 

[MauiScubaSteve]

Comments in this thread got me thinking about the problem of learning things that are wrong:
http://www.scubaboard.com/forums/ad...03129-formal-education-option-obligation.html

This made me curious about what divers were taught that was wrong as opposed to incomplete, overly simplified, a different technique, or less efficient. I have trouble recalling anything that I discovered was wrong, with the possible exception of cutting an exhaust hose on a double hose regulator being deadly on episodes of Sea Hunt.

Sure I have heard things that were really wrong in conversations (and on this board), but they didn’t stand long before somebody steeped in with the, or at least a, right answer.

So I'm wondering about relating this post to the OP (quoted above). With regards to air consumption and OOA incidents, is there something "most" divers are being taught that is wrong; that is causing OOA incidents?

 

[Hatul]

Not something I learned wrong, but something I saw taught wrong....

An AI was teaching some OW students about SAC rates. On the previous dive he had them calculate their resting SAC rates (sitting on the bottom, resting for 1 minute). He was now during their SI having them calculate their required gas for the next dive based on those resting SAC rates. :shocked2: To ignore rock bottom is one thing, but to instruct OW students who do not know any better to vastly underestimate gas consumption, and then plan dives on that faulty information (given that most of us do not own scooters and must actually "fin" to get anywhere on a dive) was ridiculously stupid and dangerous (not necessarily during the class, but for future dives conducted now with no safety margins). Not that I'm advocating it, but better to not teach SAC's at all and leave it at surface with 500psi.

One of the side benefits of diving with an AI computer is the ave SAC and peak SAC I get for each dive in the software. Even gives the gas use in cf/min and psi/min.

 

[markmantei]

I'll give the dude props for teaching it at all ... most instructors don't. I've met many who think it's not needed ... that telling someone to watch their gauge and abort the dive at 500 psi is sufficient (sure it is ... that's why OOA is so common). But it's far easier to fill in the gaps if you know a certain type of knowledge exists.

I teach that SAC rate is not a number ... it's a range, and that your actual usage depends on a lot of variables such as diving conditions, swimming speed, and several other factors that can vary day to day, dive to dive. I liken it to the MPG on your car. You can use an "ideal" number as a baseline, but then you have to factor in what's going to affect it if you want to know how far you can make it on a tank of gas.

... Bob (Grateful Diver)

Bob, first let me thank you for your article on Gas Management. I have read it several times over the last few years, and while admittedly I do not go through indepth gas planning for every dive, it has definitely informed what I consider to be minimum gas for profiles and sites I do regularly.

I have no doubt that you teach this properly and fully, and gas planning should receive more focus than it does. I am a little surprised though that you would support teaching that is incomplete. My feeling was that a little knowledge can be dangerous. Now you think you have the knowledge, but actually have no idea, in the real world, potential with no safety reserve, maybe I'm wrong. To use your MPG example, that would be like planning a trip based upon the MPG on the windows sticker, and being surprised when you run out of gas in the middle of nowhere.

Can and should gas planning be taught, absolutely, but then it should start with the theory in the classroom. Run examples. It should be done just like dive tables, lets talk theory and run some hypothetical examples, then we can apply this knowledge base to real world examples during OW training.

 

[MXGratefulDiver]

No ... you are correct. Teaching it wrong could get someone in trouble. However, it could also get that same someone to want to take a closer look at the topic. Students are generally smarter than some people give them credit for ... most have a significant self-interest in their well-being, and given the right circumstances can often ask questions that even make the instructor want to learn more.

Diving is a continuum of knowledge. To some degree we all teach things wrong ... I learned that the hard way trying to explain diving physiology to a student who happened to be a physician ... she kept correcting me. But even a simplification can serve a useful purpose ... it can open mental windows, and cause a student ... or even the instructor ... to want a closer look at what's on the other side. I'd way rather that than to have the subject ignored completely.

In my seminars I've had instructors show up who have been teaching scuba for years that never really understood this stuff. I had one about a year ago come up to me after the session and say "I came in here wondering why I would want to know this. Now I'm wondering why I haven't been teaching it all this time."

... Bob (Grateful Diver)

 

[Bob DBF]

So I'm wondering about relating this post to the OP (quoted above). With regards to air consumption and OOA incidents, is there something "most" divers are being taught that is wrong; that is causing OOA incidents?

Not so much wrong as the training environment. With training at 25' or shallower for OW, air is not much of a factor. The student checks the gauge but it dosen't change fast and the exercises and dive is over before the tank is near 500#. With all else going on the student learns the SPG check is not as important as the instructor claims.

Foward to a dive in 60' of water, engrossed in a new environment, skip a SPG check or two they would have done at 20' and with any luck they just scare the crap out of themselves when they see half the tank gone. Deeper water and less attention and it's a "come to Jesus" moment.


Bob
----------------------------
I may be old, but I’m not dead yet.

 

[MXGratefulDiver]

Not so much wrong as the training environment. With training at 25' or shallower for OW, air is not much of a factor. The student checks the gauge but it dosen't change fast and the exercises and dive is over before the tank is near 500#. With all else going on the student learns the SPG check is not as important as the instructor claims.

Foward to a dive in 60' of water, engrossed in a new environment, skip a SPG check or two they would have done at 20' and with any luck they just scare the crap out of themselves when they see half the tank gone. Deeper water and less attention and it's a "come to Jesus" moment.


Bob
----------------------------
I may be old, but I’m not dead yet.

Exactly so ... and the problem is further exacerbated when the student is encouraged to sign up for AOW directly upon completing OW, and is given the impression that after the class they are somehow qualified for dives to 100 feet. Now you have a diver with high air usage, barely developing awareness skills, very little exposure to the effects of narcosis, and usually a small rental tank. This diver is not equipped to deal with an OOA ... or more frequently an LOA ... at the depth where it's most likely to occur.

To tie this back to Markmantei's point, the diver who has been exposed at the OW level to the concepts of air management ... even if what was taught was basically flawed ... would be less likely to find themselves OOA or LOA under these circumstances, because at least they would have been taught to think about their air supply in a pro-active, rather than re-active manner.

... Bob (Grateful Diver)

 

[DaleC]

...to think about their air supply in a pro-active, rather than re-active manner.

... Bob (Grateful Diver)

Succinctly hit the nail on the head regarding the ol "back to the boat/surface with 500psi" rule.

 

[roppers]

Not being teached, but the most non divers ask me about breathing O2 as a gas.

 

[markmantei]

Another thing that pisses me off is dm's in vacation spots that put loa diver's on their octo and continuing the dive. I understand why they do it and don't fault the individual dm's, but its a bad example from someone in a position of authority, making it seem like it would be ok to just run your tank down, then just suckoff your buddies tank.