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Nitrox for shallow water artifact diving??

Discussion in 'Advanced Scuba' started by calabash digger, Jun 8, 2021.

  1. MaxBottomtime

    MaxBottomtime Divemaster

    # of Dives: 2,500 - 4,999
    Location: Torrance, CA
    The problems are funding and results. Who would pay hundreds of thousands of dollars to study something that would benefit a small fraction of the population? Also, how do you judge peoples' feelings? I've felt tired after a dive that I've made before and felt exhilarated afterward using the same gasses and profile.
  2. rx7diver

    rx7diver Solo Diver

    Just looking for a way to fund my dream of diving in the South Pacific. Surely there are aerospace implications?

    AfterDark and rmssetc like this.
  3. AfterDark

    AfterDark Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Rhode Island, USA
    So what mix would be good @ 25FSW 70% maybe 100% O2? How high is up?
  4. AfterDark

    AfterDark Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Rhode Island, USA
  5. ginti

    ginti DIR Practitioner

    # of Dives: 200 - 499
    Location: Lyon, France
    Why? Just use whatever gas you want and respect the deco rules...
    rjack321 and AfterDark like this.
  6. johndiver999

    johndiver999 Solo Diver

    # of Dives: 500 - 999
    Location: Gainesville FL
    well 100% at 25 would not be a good idea.. for long.
    shoredivr, rjack321 and AfterDark like this.
  7. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    From the Merriam-Webster dictiionary:

    However, there are two senses of theory which are sometimes troublesome. These are the senses which are defined as “a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena” and “an unproven assumption; conjecture.” The second of these is occasionally misapplied in cases where the former is meant, as when a particular scientific theory is derided as "just a theory," implying that it is no more than speculation or conjecture. One may certainly disagree with scientists regarding their theories, but it is an inaccurate interpretation of language to regard their use of the word as implying a tentative hypothesis; the scientific use of theory is quite different than the speculative use of the word.
    @AfterDark I fear you are using theory in the speculative sense, which is NOT appropriate for how it is used in the scientific context, as in "decompression theory," as @boulderjohn is using it.
    shoredivr, yle, rjack321 and 3 others like this.
  8. boulderjohn

    boulderjohn Technical Instructor ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Boulder, CO
    It depends upon your elevation.
  9. boulderjohn

    boulderjohn Technical Instructor ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Boulder, CO
    I am really baffled by this exchange. This is all standard nitrox training.

    Start with the basic equation PG = FG * P, with P expressed in ATA. If you have two of the variables, you can find the value of the other one. If we want to find the nitrox percentage (FG = Fraction of gas), we divide PG by P.

    With oxygen levels, our primary concern is not exceeding a safe gas pressure (PO2), which is usually considered to be 1.4 for active diving or 1.6 for decompression stops, so let's use 1.4 for PG. For P, we have to convert 25 feet of sea water to ATA. (It will be slightly different for fresh water.) 25/33 + 1 = 1.76. Now that we have two of the variables, we can find the third. FG = PG/P, or in this case, FG = 1.4/1.76 = 79.5.

    So a diver can safely use 80% nitrox at 25 feet on the 1.4 standard.
    rjack321 likes this.
  10. Bob DBF

    Bob DBF Solo Diver

    # of Dives: I just don't log dives
    Location: NorCal
    Depends. Using a medical definition (A condition characterized by a lessened capacity for work and reduced efficiency of accomplishment, usually accompanied by a feeling of weariness and tiredness) would be maybe, however if you were physically tested and could meet the study objective standard, you would not be fatigued, only subjectively tired. If you could not meet the physical standard you would be fatigued, as well as understandably tired.

    Or you could be in a different time zone and not acclimated yet.
    AfterDark likes this.

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