• Welcome to ScubaBoard


  1. 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. Login or Register now by clicking on the button

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

Discussion in 'Basic Scuba' started by Thalassamania, Jan 6, 2009.

  1. Miller64

    Miller64 Contributor

    # of Dives: 25 - 49
    Location: Memphis
    176
    0
    where can I find NWgratefuldiver's article?..Interested in reading it.
     
  2. eponym

    eponym Contributor

    # of Dives: 1,000 - 2,499
    Location: Oregon, USA
    1,608
    257
  3. TheWetRookie

    TheWetRookie Instructor, Scuba

    # of Dives: 500 - 999
    Location: Vancouver, British Columbia, Canada
    881
    13
    In my OW class and AOW, I do not recall doing any gas management other than knowing turn pressure. Unless I slept through that part of the course.

    Bob has a good write up on gas management and a lot more time needs to be spent on this topic in the OW course.
     
    Last edited: Jan 13, 2009
  4. nereas

    nereas Contributor

    # of Dives: 500 - 999
    Location: Expat Floridian travelling in the Land of Eternal
    2,735
    6
    Azimuth straight out and back, and SPG for rule of halves (turning around at 1/2 SPG minus a small reserve) or rule of thirds is all you really need for NDL.

    Until and if you get into tech diving, anything else would be a waste of time in OW1 or AOW.
     
  5. eponym

    eponym Contributor

    # of Dives: 1,000 - 2,499
    Location: Oregon, USA
    1,608
    257
    Crikey.

    I might be troll-feeding, but . . .

    That's not gas planning, that's gas management.

    Managing your gas is deciding on the fly whether you still have enough, whether it's time to head home.

    Planning your gas is considering what you've got on your back when you're still deciding where & how deep you'll go.

    For example, "never make a dive deeper than the number of cubic feet on your back."

    That's a rudimentary but useful planning rubric. No math, no consumption rates, no rock bottom calcs, but still a consideration in the planning stage.

    The best thing I took from SB last year was that my open water classes should give as much attention to gas planning as to coping with out-of-air scenarios.

    -Bryan
     
  6. nereas

    nereas Contributor

    # of Dives: 500 - 999
    Location: Expat Floridian travelling in the Land of Eternal
    2,735
    6

    I have no doubt that your definitions are correct. I simply dispute that teaching OW1 students more than rule of halves (turning at 1/2 SPG less a small reserve) is appropriate or even necessary. Not trolling. Not even arguing with you. Just disagreeing.
     
  7. eponym

    eponym Contributor

    # of Dives: 1,000 - 2,499
    Location: Oregon, USA
    1,608
    257
    Fair enough. And thanks for the quick reply. I assume that "OW1" means the full open water diver certification course?

    In my open water classes I try to give students a glimpse of the wider world of diving: archaeological, scientific, deco, wreck, and other diving pursuits; rebreathers, drysuits, doubles, and other gear choices; and further dive training and dive planning approaches. Gas planning is part of that.

    And for me gas planning is also a piece of the whole buddy team / dive planning gestalt in the open water diver course. I can't see how that could be considered "inappropriate." Could you amplify?

    Cheers,
    Bryan
     
  8. Thalassamania

    Thalassamania Diving Polymath ScubaBoard Supporter

    # of Dives: 5,000 - ∞
    Location: On a large pile of smokin' A'a, the most isolated
    22,171
    2,774
    I go through the entire process of determining Bingo Air for three different depths, no-D, open water. The output of that is that the new divers see that for OW diving, no-D, etc., your rule is perfectly resonable, but they also get to see why as well as how to do it for real.
     
  9. ZzzKing

    ZzzKing Contributor

    # of Dives: 200 - 499
    Location: Dallas
    2,491
    135
    "How & Why" v. just "What" is probably also the difference between a good teacher and just an adequate teacher.
     
  10. nereas

    nereas Contributor

    # of Dives: 500 - 999
    Location: Expat Floridian travelling in the Land of Eternal
    2,735
    6

    Inappropriate in the sense that it goes beyond their ability to absorb and utilize it during their first course.

    It is more appropriate to leave that concept for later courses.

    Most appropriately either master diver or deco.
     

Share This Page