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

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Thalassamania

Diving Polymath
ScubaBoard Supporter
Messages
22,171
Reaction score
2,774
Location
On a large pile of smokin' A'a, the most isolated
# of dives
5000 - ∞
These posts have been graciously moved by Teamcasa from another thread where they were a bit off topic.

-------------------------------

... However, there are some - intelligent, capable people - who do not see this as flexible, but as restrictive. And, in good conscience, those individuals probably are not comfortable agreeing to do things PADI's way.

...

I would not require them to perform a gas calculation exercise, and then deny them certification if they could not perform it - that would be exceeding standards. But, that is part of the presumed flexibility of the system, I guess - I also would not criticize the instructor you reference, for their conclusion that it would be exceeding standards.
I find it hard to believe that someone can become a "certified" diver who can not perform a simple gas calculation and that intelligent people can stand around and wring their hands over whether such gas calculations are "elaborations" of "exceedings," and thus permitted or prohibited. In my view this is foolishness bordering on the medieval Scholastic.
 
Last edited by a moderator:

KrisB

Contributor
Messages
3,507
Reaction score
15
Location
Edmonton, Alberta, Canada
# of dives
500 - 999
I find it hard to believe that someone can become a "certified" diver who can not perform a simple gas calculation and that intelligent people can stand around and wring their hands over whether such gas calculations are "elaborations" of "exceedings," and thus permitted or prohibited. In my view this is foolishness bordering on the medieval Scholastic.
I've met successful people who still (in their late 20's) struggle with pre-algebra.

Are you saying that these people shouldn't be divers since they don't get the ridiculous mathematical calculation of air consumption well enough?
 

Thalassamania

Diving Polymath
ScubaBoard Supporter
Messages
22,171
Reaction score
2,774
Location
On a large pile of smokin' A'a, the most isolated
# of dives
5000 - ∞
It's not a ridiculous calculation and I'd not certify them to dive independently, no way. But then I think that people should be able to swim also.
 

KrisB

Contributor
Messages
3,507
Reaction score
15
Location
Edmonton, Alberta, Canada
# of dives
500 - 999
It's not a ridiculous calculation and I'd not certify them to dive independently, no way. But then I think that people should be able to swim also.
For a new diver to accurately calculate a SAC rate... yeah, it's a pretty ridiculous expectation, not to mention pretty pointless.

Why do I say this? For several reasons:
1. unless you have an accurate average depth (i.e. square profile, exact record of a multi-level profile, or a computer), the best you can get is a rough estimate. At worst, it's no better than a WAG.

2. a new diver's SAC is going to change (both up and down) on every dive for the first spell. To that extent, it's useless for dive planning.

3. with the lack of accuracy and uselessness in planning at the stage they're at, a SAC calculation is not likely to be remembered beyond when the diver needs it to pass the exam.
 

Thalassamania

Diving Polymath
ScubaBoard Supporter
Messages
22,171
Reaction score
2,774
Location
On a large pile of smokin' A'a, the most isolated
# of dives
5000 - ∞
There's a piece that you missed, the ability to calculate a SAC rate and manipulate its variables is a demonstration of a clear understanding of a number of very important diving concepts. If your students can not, or does not, remember how to do a SAC calculation beyond their exam, I would see that as just one more in a long list of your failures to adequately prepare your divers. I truly feel sorry for them, its realy a shame that they hooked up with an instructor who can't explain the concepts in a memorable fashion using nothing more than simple multiplication, division, addition and subtraction ... truly a shame.
 

KrisB

Contributor
Messages
3,507
Reaction score
15
Location
Edmonton, Alberta, Canada
# of dives
500 - 999
There's a piece that you missed, the ability to calculate a SAC rate and manipulate its variables is a demonstration of a clear understanding of a number of very important diving concepts. If your students can not, or does not, remember how to do a SAC calculation beyond their exam, I would see that as just one more in a long list of your failures to adequately prepare your divers. I truly feel sorry for them, its realy a shame that they hooked up with an instructor who can't explain the concepts in a memorable fashion using nothing more than simple multiplication, division, addition and subtraction ... truly a shame.
Again, Thal... if you truly have the experience in academia that you suggest you do, you'd understand that unless the concept is usable, useful and used regularly, it won't be remembered beyond when it's needed.

Usually that is just until the last time it's tested for passing or failure.

Of course, if you think your students still remember everything you taught them, I'd say you're proving your delusion to be greater than that which I'd be even remotely capable of.
 

Thalassamania

Diving Polymath
ScubaBoard Supporter
Messages
22,171
Reaction score
2,774
Location
On a large pile of smokin' A'a, the most isolated
# of dives
5000 - ∞
It 'aint rocket science. If you are so enfeebled that you can not add, subtract, multiply and divide, as well as intuitively know if a bubble gets bigger on the way up and smaller on the way down, and have not memorized a few critical values like 1 atm per 33 feet, then as far as I'm concerned you have no business diving and I will not certify you. You do not meet my minimum standards. Now the reality is that I've never had a student, including 10 and 12 year olds, that I could not easily teach this to, so I never actually had to test my resolve on this issue.
 

KrisB

Contributor
Messages
3,507
Reaction score
15
Location
Edmonton, Alberta, Canada
# of dives
500 - 999
It 'aint rocket science. If you are so enfeebled that you can not add, subtract, multiply and divide, as well as intuitively know if a bubble gets bigger on the way up and smaller on the way down, and have not memorized a few critical values like 1 atm per 33 feet, then as far as I'm concerned you have no business diving and I will not certify you. You do not meet my minimum standards. Now the reality is that I've never had a student, including 10 and 12 year olds, that I could not easily teach this to, so I never actually had to test my resolve on this issue.
We're not talking about the individual operations or constant memorisation.

We're talking about dealing with a formula and plugging in certain values in specific spots.
 

Thalassamania

Diving Polymath
ScubaBoard Supporter
Messages
22,171
Reaction score
2,774
Location
On a large pile of smokin' A'a, the most isolated
# of dives
5000 - ∞
We're not talking about the individual operations or constant memorisation. ...
Of course we are. Once again you demonstrate a basic lack of pedagogical technique and understanding. But that's what prescriptive "teaching" is all about, no? Permitting the incapable to attempt to teach the unknowing.

Plugging numbers into formulas to see if you can mechanically crank out the correct answer is complete and utter BS. Using basic knowledge of intuitive physics and basic mathematical functions to solve a problem, on the other hand, not only demonstrates an understanding of the topic but also builds strong memory patterns for remembering it in the future.
 

KrisB

Contributor
Messages
3,507
Reaction score
15
Location
Edmonton, Alberta, Canada
# of dives
500 - 999
Of course we are. Once again you demonstrate a basic lack of pedagogical technique and understanding. But that's what prescriptive "teaching" is all about, no? Permitting the incapable to attempt to teach the unknowing.

Plugging numbers into formulas to see if you can mechanically crank out the correct answer is complete and utter BS. Using basic knowledge of intuitive physics and basic mathematical functions to solve a problem, on the other hand, not only demonstrates an understanding of the topic but also builds strong memory patterns for remembering it in the future.
Again, Thal... the reasoning skills you're adding here are going beyond the level of most high-school graduates.

Oops. I sense a diatribe on how the high-school graduation standards have fallen over the last 50 years, and how that's leading to the downfall of the world.
 
https://www.shearwater.com/products/peregrine/

Top Bottom