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Diving and flying

Discussion in 'Decompression Theory' started by Sbiriguda, Dec 3, 2020.

  1. Landau

    Landau Divemaster

    # of Dives: 200 - 499
    Location: Vancouver
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    350
    I'd also like more info on this. I've never heard of it before. I've done my first dive on a liveaboard somewhere around 5 hours after getting off the plane.
     
    grantctobin likes this.
  2. scubadada

    scubadada Diver Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
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    10,637
    Hi @Sbiriguda

    In the end, your choices are your own and you take responsibility for them.

    I dive pretty aggressively with fairly liberal computers, I take that risk. However, I have never skipped a deco stop and I have never violated the no fly rules.

    Though I have always followed the no fly rules, I have often noted the desaturation times displayed by some of my dive computers. I have never read about the accuracy of these calculations and would not rely on them. Sometimes they have been lower than the suggested no fly times, sometimes they have been higher. Of note, I have been able to generate desaturation times of greater than 24 hours on numerous occasions. Most eye opening is that when diving two different brands of computer, there have frequently been very significantly different displays of desaturation time. My Shearwater Teric does not display a desaturation time. Shearwater recommends following the recommended no fly times, erring on the conservative side. However, I can take a look at the tissue loading graphic.
     
    lexvil, Esprise Me and Sbiriguda like this.
  3. Sbiriguda

    Sbiriguda Contributor

    # of Dives: 25 - 49
    Location: Italy
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    I just remember this as a recommendation (not mandatory as I said in the beginning), perhaps it was meant only for long flights like you said
     
  4. Searcaigh

    Searcaigh Chromodoris gordonii Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Dubai, UAE
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    Really?

    There are some good wrecks around Aqaba, but I wouldn't fly there for a weekend.
     
  5. Mike Beck

    Mike Beck Registered

    10
    6
    Really the only issues with diving after flying is fatigue and dehydration.
     
  6. ontdiver

    ontdiver Solo Diver

    # of Dives: 200 - 499
    Location: Ottawa, Ontario
    580
    380
    While I get it that some folks are curious about what is involved in pushing the envelope - after all, the backdrop to diving is physics, engineering, etc - I would really prefer that those who want to violate no fly rules first consider the impact that their decision may have have on medical resources that are heavily strained.
     
    NelleG and Sbiriguda like this.
  7. boulderjohn

    boulderjohn Technical Instructor ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Boulder, CO
    27,132
    20,265
    My resource page has an article on ascending to altitude after diving that my help you. It includes the US Navy information Tursiops mentioned earlier.

    The diving you describe here is well within the US Navy limits, and it is within the PADI and DAN America recommendations. It is outside the DAN Europe recommendations, which are very conservative.
     
    couv and Sbiriguda like this.
  8. Angelo Farina

    Angelo Farina Marine Scientist

    # of Dives: 1,000 - 2,499
    Location: Parma, ITALY
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    As for the dive in the morning, and then flying in the late afternoon or evening, I would prefer a short, deep dive than a long dive at shallow depth.
    The first will load of nitrogen your fast tissues, which will desaturate quickly. Instead, a long dive at, say, less than 10 meters, causes your slow tissues to get a significant amount of nitrogen. This will last in your body for several hours...
    Modern "tech" computers should allow you to see the amount of nitrogen still remaining in each of your tissues (called often "compartments" on computers) after surfacing. When they all are at zero, you can fly safely.
    You can also use some existing Excel spreadsheet for running simulations, and verify what I affirmed here above.
     
  9. NothingClever

    NothingClever ScubaBoard Sponsor ScubaBoard Sponsor

    # of Dives: 200 - 499
    Location: Red Sea and Atlantic Ocean
    938
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    @Sbiriguda

    What gas are you breathing on your last dives?

    Staying shallow is obviously smart. If I'm not mistaken, tissue loading doesn't happen in earnest until 8m so staying shy of that is helpful.

    But if you're pushing the time envelope, I'd get off the 21% and breathe a higher EANX gas. It won't eliminate the possibility of problems but will likely decrease tissue loading, mitigate the probability of problems occurring and the severity if a problem does occur.

    Obviously you have to gauge your own levels of risk and be scientific about implementation of the measures to mitigate problems (ie., setting hydration goals and counting your liters, undistracted sleep, don't be a dork and booze it up, etc). I think walking several kilometers sometime after your dive is also helpful to stimulate N2 dissipation.

    Might be wise to find a pilot that dives to figure out how they mitigate tissue problems.
     
    Sbiriguda likes this.
  10. Angelo Farina

    Angelo Farina Marine Scientist

    # of Dives: 1,000 - 2,499
    Location: Parma, ITALY
    1,758
    2,687
    Well, if you dive with a CC pure oxygen rebreather (ARO) you will not get any Nitrogen added.
    Current recommendations are to not exceed 6m depth with these units, albeit I am certified for using them down to 10m.
    When young, I and my wife did use them several times down to 12m, with the trick of starting with
    the counterlung full of air, instead of pure oxygen.
    CC Rebreathers require specific training, but can be the solution for your problem.
    You could also consider Nitrox at 50% in OC.
    It has a maximum depth of 22m (at ppO2=1.6 bar), but you should stay much shallower if you want to keep the ppN2 as the same value as atmospheric air, that is 0.78 bar. You reach this pp at approximately 6 m.
     
    DiveClimbRide and Sbiriguda like this.

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