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Question for Mexican Cavers

Discussion in 'Cave Diving' started by SavDiver, Jan 31, 2021.

  1. SavDiver

    SavDiver Instructor, Scuba

    # of Dives: 500 - 999
    Location: Florida
    98
    25
    About 2 weeks ago I came across 2 or 3 videos on youtube of people diving in Mexico. I noticed that their al80 said 55%. With that being said do you guys down south seriously run that high percent? I figured you guys would be good at even 32% considering all the stories I hear is every cenote runs around 30 foot.
     
  2. Manatee Diver

    Manatee Diver Stop throwing lettuce at me! ScubaBoard Supporter

    # of Dives: None - Not Certified
    Location: Tampa Bay, FL
    2,104
    2,016
    32% was the standard nitrox mix at most operators. You can request custom mixes for an upcharge.

    I remember discussion I had with Roger Williams he postulated that you could breath 50% at a shallow cenote like Nohoch and immediately get onto an airplane. Maybe someone turned his postulation into reality?

    Though I think it is probably pointless because I remember ending a 2 hour dive at Nohoch on standard nitrox at 2% surface gradient factor. I probably wouldn't have any DCS issues on an airplane with that low of a nitrogen loading.
     
  3. dewdropsonrosa

    dewdropsonrosa ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Chicago, IL
    474
    748
    Is there any chance that it was 55m, instead of percent?

    55m = ~180 feet, around which depth air has a PPO2 of 1.4.
     
    RainPilot, Miyaru and DiveClimbRide like this.
  4. rddvet

    rddvet DIR Practitioner

    # of Dives: 50 - 99
    Location: Florida
    1,505
    1,418
    In years of Mexico diving I’ve never seen anyone run 55%. Hell I’ve rarely seen anything but air or 32%. I’d bet as said above it was an 55meter mod.
     
  5. SavDiver

    SavDiver Instructor, Scuba

    # of Dives: 500 - 999
    Location: Florida
    98
    25
    Nope, it was defiantly 55% cause it was a piece of masking tape.
     
  6. SavDiver

    SavDiver Instructor, Scuba

    # of Dives: 500 - 999
    Location: Florida
    98
    25
    I mean if you got the money and you stay in your ppo2 then who cares right? lol. That would be an exciting subject for the matter. Could the same be said if you just breath straight o2 out of the water for x amount of time. I don't think it would be possible to be 100% cleared while underwater cause even at 15-20feet you technically still are taking in some n2 load just not much.
     
  7. rjack321

    rjack321 Captain

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, Washington State
    10,982
    5,641
    Its not common to use 50% as a deco gas in MX. But if someone were to ask for 50% the chances of the mix being off by 5% are high - i.e. significant mis-mixing down there is common. Perhaps it was intended as a deco gas for a long swim back from someplace like the Pit. Not everything is shallow. On the other hand idiots abound so who knows
     
  8. Norwegian Cave Diver

    Norwegian Cave Diver ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Calgary Alberta Canada
    505
    304
    I can think of two locations where doing deco at 20 feet with two divers there isn’t much room. Divers would be doing deco in a vertical position vs horizontal. This could be a reason to have a different deco mix vs 100. But cave diving 32 is by far the most common gas mix available. You would need to ask to get something different.
     
  9. oya

    oya Rebreather Pilot

    # of Dives: 2,500 - 4,999
    Location: Akumal, MX
    336
    517
    It’s a bit of an overstatement that every cenote is 30 feet, but not too far off.

    That said: 32% is the norm here. 55% as a gas is super weird.

    If it was just a giant piece of tape (masking or not) and all it said was “55” I’m gonna +1 the theory it was an MOD sticker for 21/35 or something. MODs are in meters here.

    Also: my theory on 50% and driving straight to the airport is an intellectual exercise only. Do not try this at home.
     
  10. SavDiver

    SavDiver Instructor, Scuba

    # of Dives: 500 - 999
    Location: Florida
    98
    25
    I'm gonna try to find the videos ill let you know if I find them and ill post a link to them but I believe it said % not M or FT. Mexico is definalty on my bucketlist, after I get a rebreather lol.
     

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