• 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

Nitrox certification

Discussion in 'Pacific Northwest' started by Andre_N, May 13, 2019.

  1. Seaweed Doc

    Seaweed Doc Marine Scientist

    # of Dives: 500 - 999
    Location: Seattle, Washington State, USA
    676
    425
    63
    Interesting! The class I took tested us on calculating the appropriate oxygen partial pressures by hand, rather than looking them up. (Maybe there was a table as well.) I'd have thought calculating the values is more flexible (and perhaps more difficult?) than looking them up on the table.
     
  2. g2

    g2 Divemaster

    # of Dives: 500 - 999
    Location: Port Townsend, WA
    559
    84
    28
    Yup, we calculated them by hand too. But I think I've used that only a couple times in the past 25+ years, and then only out of curiosity or some unusual dive planning. I would argue that, at least for typical recreational nitrox dives, hand calculation is unnecessary and more error-prone than using tables.

    (But still a worthy thing to know in case you find yourself without a table and your lovely nitrox computer has conked out.)
     
  3. Streydog

    Streydog Manta Ray

    # of Dives: 200 - 499
    Location: DFW, TX
    770
    469
    63
    If my lovely nitrox computer conks out I will still know what my MOD is from memory, But that would not do me much good because I count on my lovely computer to know what depth I am at. I do dive with two computers though.
     
    chillyinCanada likes this.
  4. Seaweed Doc

    Seaweed Doc Marine Scientist

    # of Dives: 500 - 999
    Location: Seattle, Washington State, USA
    676
    425
    63

    On the other hand, the LDS has a table posted at the EANx logbook. That should help reduce the risk of calculation errors.

    I suppose everything has it's place.
     
  5. chillyinCanada

    chillyinCanada Solo Diver Staff Member

    14,812
    9,312
    113
    I still have my lovely spg to go with my two lovely nitrox computers but yes, MOD is in my memory bank . . .at least for the time being.
     
  6. bravokiloromeo

    bravokiloromeo Angel Fish

    # of Dives: 50 - 99
    Location: Ann Arbor
    63
    2
    8
    @Andre_N: Pretty much all the Nitrox courses are the same. You learn about the advantages and disadvantages to enriched O2 levels, PPO2s, and oxygen toxicity signs/symptoms. I believe the online (at least my SSI online class required it) and in-person classes all require you to analyze a tank to understand how to do it (what you do when you start getting Nitrox fills at a shop/boat), as well as set your computer into the Nitrox mode. It's at best a half-day class with 0 mandatory dives involved.

    I will also throw my hat in the ring for 8. I'm a fairly frequent customer when I'm up in Seattle, and I've met/dive with several (most?) of the NAUI instructors there (Bert, Clay, and James) and they're all awesome folks. Most of the NAUI guys are also GUE tec certified divers (James is working on his GUE rec instructor cert IIRC) so they're very skilled in the water and the kind of people you want to learn from.
     
  7. Andre_N

    Andre_N Nassau Grouper

    # of Dives: 100 - 199
    Location: Seattle
    81
    16
    8
    Good to know. Thanks!
     
  8. TheZissouSociety

    TheZissouSociety Garibaldi

    # of Dives: 25 - 49
    Location: Seattle, WA
    2
    1
    3
    I ended up doing mine fairly recently at Silent World over in Bellevue. It was a SDI course.
     
    Andre_N likes this.
  9. Andre_N

    Andre_N Nassau Grouper

    # of Dives: 100 - 199
    Location: Seattle
    81
    16
    8
    How many hours?
     
  10. wetb4igetinthewater

    wetb4igetinthewater Instructor, Scuba

    # of Dives: 500 - 999
    Location: Seattle
    3,577
    1,819
    113
    @Andre_N,

    From my experience (teaching for PADI, SSI, and SDI), nitrox is all fairly similar across most agencies. There is measuring the oxygen mixture in your cylinder which you SIMPLY MUST ALWAYS DO (or observe it being measured). Never, ever, trust anyone who tells you it is already done. To calculate your MOD, you can calculate on paper, use an app, or your dive computer. Then, there is the paperwork where you provide your cert number, fill out the O2 percentage, MOD, cylinder serial number, sign & date (probably mostly for the US for the nitrox source to protect themselves).

    Some instructors teach tables, others just do the computer only version. I like to teach tables for background and some of the math.

    The number of hours does vary dramatically. My longest class was actually a 1:1 class where the student wasn't retaining things for very long. I just kept rotating the questions until they got it. Honestly, after the items in the first paragraph, I suspect he doesn't remember all the academic stuff, and for most people, that is fine. If you get into technical diving, you will revisit it.
     

Share This Page