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What is the deepest you have been on pure O2?

Discussion in 'Technical Diving' started by CAPTAIN SINBAD, Nov 23, 2015.


    CAPTAIN SINBAD Divemaster Candidate

    # of Dives: 200 - 499
    Location: Woodbridge VA
    So it seems like when Po2 is assumed to be 1.4 then MOD for pure oxygen is 13 feet but when we assume po2 of 1.6 then it is 20! A 7 foot deviation seems a bit too much so can anyone explain how deep can you be while you decompress on pure O2? Thanks.
  2. decompression

    decompression Instructor...seriously...

    # of Dives: 5,000 - ∞
    Location: Victoria, BC, Canada
    Obviously the recommendation is 20', although there are many that have routinely used O2 to 30, 40 even 50'.

    Sent from my iPhone using Tapatalk
  3. hroark2112

    hroark2112 Tech Instructor

    # of Dives: 0 - 24
    Location: Raleigh, NC
    I've done 60' on 100% O2 but that was in a chamber. Didn't tox, but you won't catch me trying it in the water!
    DogDiver likes this.
  4. jbomb001

    jbomb001 Solo Diver

    # of Dives: 100 - 199
    Location: norther new york
    I would recommend a good intro to tec. Class if you have not already taken one and if you have taken one take another as this should have been covered in said class..

    Sent from my SAMSUNG-SM-G870A using Tapatalk
    lindenbruce likes this.
  5. Nasser

    Nasser ScubaBoard Supporter ScubaBoard Supporter

    1.4 is typically the recommended pp02 limit for any gas used during the bottom phase of a dive (sometimes 1.3 or even 1.2 is used). During the decompression phase when nitrox or 02 is used as a deco gas then 1.6 is the recommended limit - so yes, that gives you an MOD of 20 ft. In the past I believe the Navy was using 2.0 as the limit and of course in a chamber or on surface the limit can be above 2.0 but that is done very gradually and with medical supervision. An O2 hit on the surface is obviously not as dangerous as during a dive.
    shoredivr likes this.
  6. ajduplessis

    ajduplessis Solo Diver

    # of Dives: I'm a Fish!
    Location: dry land :-(
    I use O2 @ 20 feet regularly and have used O2 in camber down to 60. Perform air breaks every 12-15min to better manage your exposure and deco efficiency.
  7. Peter69_56

    Peter69_56 Divemaster

    # of Dives: 500 - 999
    Location: Australia
    On diving HMS Repulse the deco bar was affected by current and set at 6 metres but while we were decoing the current dropped off and the bar dropped to 7m (23') and my shearwater started telling me I was going to die.

    Fate stepped in (along with some common sense) and I managed to get back to 6m and survive.
    Searcaigh likes this.
  8. JamesDownUnder

    JamesDownUnder Registered

    In the hyperbaric chamber, they had us on 100% O2 at 22m equivalent depth. This was with a critical care nurse, a crash cart and a whole heap of monitoring gear taped to me. Not a lot of fun, and certainly never something I'd try in the water.

    Posting from my iPad, please excuse unfortunate iCorrects.
    Lorenzoid likes this.
  9. PfcAJ

    PfcAJ Contributor

    # of Dives: 5,000 - ∞
    Location: St Petersburg, Fl
    30ft in a habitat. Wouldn't sign up for that without the habitat.
    Last edited: Nov 24, 2015
  10. kensuf

    kensuf ScubaBoard Sponsor ScubaBoard Sponsor

    I toxed in a chamber at 60' on O2. No bueno, and I do not recommend it.

    Breathing O2 underwater at a PO2 > 1.6 (20') is a foolish game. Some people may have gotten away with it, but there are several dead guys that did not. The reasons why chambers provide O2 at 60' is because (a) you're less susceptible to toxing while dry, and (b) if you do tox, you're not going to drown.

    BTW -- no one is completely sure why you're more susceptible to toxing while wet, but I vaguely recall some people hypothesizing that the mammalian diving reflex may contribute to it.
    northernone likes this.

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