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Gas mix

Discussion in 'SDI/TDI/ERDI' started by stevensamler, Oct 27, 2019.

  1. stevensamler

    stevensamler DIR Practitioner

    # of Dives: 200 - 499
    Location: Culver City, California, United States
    270
    74
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    Hello , I'm curious as to what gas mix for back gas does TDI use for AN/DP classes?
     
  2. Superlyte27

    Superlyte27 Cave Instructor

    # of Dives: 5,000 - ∞
    Location: Florida
    3,631
    2,631
    113
    Gas appropriate for the planned depth of the dive.
     
  3. broncobowsher

    broncobowsher Solo Diver

    1,043
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    Ask your instructor. Often it is just air. Put some helium into it and you are starting a trimix class.
    What about your deco gas? Somewhere between 50-100%, again you need to talk with YOUR instructor. It should be part that involves dive planning. Classroom time.

    If your instructor expects you to have everything before you start, but doesn't talk with you about what you need, you got the wrong instructor.
     
  4. abnfrog

    abnfrog Tech Instructor

    # of Dives: 2,500 - 4,999
    Location: great white north
    1,422
    876
    113
    if its advanced nitrox you use nitrox and deco u use a higher than back gas......go figure
     
  5. Mark Powell

    Mark Powell Scuba Media & Publications

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    TDI doesn't dictate the gas you use. The syllabus covers the differences in using air and nitrox and how to calculating the best mix nitrox for any depth. It also covers the differences in using a best mix or standard mix approach. The Helitrox option also covers the advantages of using a weak trimix mix at these depths.

    We give you the information and then you make the choice.
     
  6. tjeastgate

    tjeastgate Angel Fish

    # of Dives: 200 - 499
    Location: California
    13
    3
    3
    TDI doesn't use standard mixes
     
  7. abnfrog

    abnfrog Tech Instructor

    # of Dives: 2,500 - 4,999
    Location: great white north
    1,422
    876
    113
    no they don't ,
     
  8. stevensamler

    stevensamler DIR Practitioner

    # of Dives: 200 - 499
    Location: Culver City, California, United States
    270
    74
    28
    So basically EAN to 5.54 ATA . What about gas density and END for deep dives?
     
  9. kierentec

    kierentec Captain

    # of Dives: 5,000 - ∞
    Location: High Springs, FL; Tulum, Mexico
    369
    205
    43
    TDI does not currently consider END or gas density as limitations in their curriculum. There is still an extended range course available, which is air to 180ft.
     
  10. tjeastgate

    tjeastgate Angel Fish

    # of Dives: 200 - 499
    Location: California
    13
    3
    3
    Let me clarify, TDI doesn't FORCE you to use standard mixes.
     

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