Gas planning and the associated math - controversies over need and how to teach

[gcbryan]

I don't see how teaching gas management can be a problem for OW students. It's not a matter of math. I'm not good with math. Anyone can do simple math however. What matters is how it's taught. If the concept is taught then anyone can do the math to verify they have the correct answer.

Once the concept is grasped the math almost doesn't even need to be applied on a daily basis. Most people dive within a common band of depth/time combinations depending on their most common dive sites.

Once you figure out "rockbottom" for 100fsw you don't have to do it again. Once you figure it out for 60 fsw you don't have to do it again. Once you settle in to diving and figure out your SAC rate range you only need to recheck it on occasion.

What matters is that you can visualize the multiplying effect of atmospheres on your gas consumption. Most people who aren't good at math are good at visualizing things. A good teacher who actually understands their subject should be able to teach these concepts regardless of a diver's math skills.

As someone mentioned, since most people are Nitrox certified there is no excuse for not covering gas management in OW regarding math skills since everyone seems to get through Nitrox class one way or another.

As someone else posted, there are online calculators for SAC rate if that's needed. It's the concept that matters. After one understands the concept they can apply it even if they don't think in terms of formula's.

I don't see how one could argue that every diver shouldn't be able to tell you roughly in advance of a multi-level dive how much gas would be needed for each part of that dive resulting in that dive being successfully completely with gas left in the tank.

That's not saying that you actually have to go through the calculations for every dive because many dives are the same but the concept should be understood and the concepts are easily understood.

Now if we could just get away from teaching fin pivot's and Buddha style buoyancy control!

 

[Melicertes]

Now if we could just get away from teaching fin pivot's and Buddha style buoyancy control!

Hey I like my Buddha hover. Took me forever to get it right too when I started diving. :mooner:

 

[Thalassamania]

Hey I like my Buddha hover. Took me forever to get it right too when I started diving. :mooner:

I suggest that you hold that pose until you attain true enlightenment.

 

[Blackwood]

If dive agencies don't deem it necessary to teach the exceedingly basic concept of gas planning, that's their prerogative. But I'd appreciate it if they removed such phrases as "plan your dive and dive you plan" from their literature.

My favorite analogy goes something like: telling a BOW student to surface with 500 PSI remaining without an adequate discussion of consumption rates is like telling a lost traveler to turn left three miles before the Old Johnson Mill.

 

[dumpsterDiver]

I've thought this over carefully and changed my mind. I might be willing to certify a student who was so math impaired that he or she could not do the calculations. I believe in custom built divers, hand-made, one at at time. Just as I have certified students who were comfortable in the water but who were not the world's greatest swimmers, I could see my way clear to do the same here if I felt that the they understood their impairment and had a clear plan for how to keep it from getting them in trouble. This might mean always diving with a much larger tank than their buddy, or always diving with a pony, or ... ? I'm not sure, but if I am faced with the situation (in something other than the hypothetical) I will handle it differently than I would have two days ago. Just how ... I'm not sure yet.

The answer is EASY! Just make them dive with an air integrated computer

 

[Melicertes]

I suggest that you hold that pose until you attain true enlightenment.

I've tried. My legs start cramping up and before long I start thinking that attaining enlightenment is too much work down the roundabout road. So I inevitably conclude that you either are enlightened or you are not, it's a matter of waking up and realizing there is no spoon. So far my spoon's not been bending the way it did for Neo just yet but I'll keep checking my cutlery drawer from time to time

 

[Thalassamania]

The answer is EASY! Just make them dive with an air integrated computer

Is that one of them darn equipment solutions to a skills problem?

 

[dumpsterDiver]

I was taught in an open water course to assume a sac rate of about 1.0. The instructor said that is a pretty good guess and unless you swim really hard, you probably won't get in too much trouble. Teaching students to do the math with a sac of 1 cu-ft/min and then give them a simple table of rock bottom for different tanks seems like a decent compromise to me.

They learn to do VERY simple math and have a single table to refer to in the future that tabulates tanks versus depth and where they intersect is the pressure to start the ascent.

If they ever advance they can make corrections for their own consumption rate.

 

[Melicertes]

If dive agencies don't deem it necessary to teach the exceedingly basic concept of gas planning, that's their prerogative. But I'd appreciate it if they removed such phrases as "plan your dive and dive you plan" from their literature.

My favorite analogy goes something like: telling a BOW student to surface with 500 PSI remaining without an adequate discussion of consumption rates is like telling a lost traveler to turn left three miles before the Old Johnson Mill.

Well put Blackwood.

 

[Pearldiver07]

Oddly enough, this post seems to have started with thinking that teaching gas consumption may be beyond PADI standards.

Making a student pass a test using SAC rates and other related formulae may be, but introducing gas consumption is a logical step following the OW lesson about how air compresses at depth, etc. is a perfect place. If your diver doesn't know that his/her air will be breathed out twice at fast at 4 atm thatn at 2 atm, then you're doing them a disservice.

I can't remember a class when someone didn't ask about how long a dive will last. This is when I first bring up how deeper dives make you consume air faster, and how we'll cover that during the course.

Remember, this is relevant information. Testing an alghorythm is not part of the PADI OW course, however. But I do agree with several posters that OW courses aren't preparing divers for solo diving. But it does prepare them to dive and learn the necessary skills and experience to become a proficient diver.

next?