I-169 truuk lagoon

Discussion in 'Book and Media Reviews' started by tracydr, Jun 11, 2012.

  1. tracydr

    tracydr Divemaster

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    Watching this on Netflix and I have a question. It's had 130 feet and John Chatterton is clearly using Nitrox for the penetration of the submarine.

    Can somebody please give me a good reason for this?
     
  2. Boiler_81

    Boiler_81 Nassau Grouper

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    What is the name of the show are you watching on Netflix?
     
  3. RJP

    RJP PADI Pro

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    Interesting, how did you analyze his gas over Netflix? There'd be no other way for it to be "clear" that JC was breathing nitrox. Also, by "nitrox" are we to assume you mean "enriched air nitrox"?

    That said, the reason to use EANx on this dive is the same reason that you'd use nitrox on any dive: reduce nitrogen loading.

    What issue do you see with using EANx on this dive? I did two dives on the 1-169 using EANx 28%. This is considered a "standard mix" for wrecks in the 130fsw range here in NJ. In fact, you'll ofter hear 28% referred to as "a Jersey mix."
     
  4. tracydr

    tracydr Divemaster

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    One of the Deep Sea Detectives episodes.
    he had a big, green and yellow label that actually said "Nitrox" on his tank. I was able to read the label quite clearly when he was getting ready to enter the water and saw the label as he was penetrating the hull.
    Of course, no idea what mix it was. He had a single tank and the other guy had a RB, which he removed to don a little, single tank to do his penetration.
    John penetrated and completed his dive on the same tank he splashed with, the "Nitrox" tank.

    ---------- Post added ----------

    This is what I was asking. I wasn't sure exactly how deep it was and it seemed somewhat deep for Nitrox, especially if it was 32 or 38%.
    I've gone down to 130 on a couple of dives in Bonaire with Nitrox but it was only for a few minutes each time.
     
  5. RJP

    RJP PADI Pro

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    The label on the tank tells you NOTHING about what's in the tank. A nitrox label tells you that the tank has been cleaned and serviced to accommodate "enriched air" nitrox blends of greater than 21%, but that doesn't mean that a tank with such a sticker MUST contain enriched air nitrox. I have two sets of doubles in my garage right now. Great big nitrox stickers on them. The gas in them is 21%... which IS "nitrox" by the way, just not "enriched."

    Have you not covered topics related to EANx in your dive education as of yet?
     
  6. tracydr

    tracydr Divemaster

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    Thanks. I've not seen Nitrox tanks filled with 21%, although I know they can be.
    And yes, I have covered this. I just saw the label and made the assumption that he was diving enriched air, rather than 21%.
    like you say, I can't analyse the tank on TV. But, also didn't know that Jersey Wreck divers typically dive 28%.
    i always learn something. No need to chastise.
     
  7. RJP

    RJP PADI Pro

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    Wasn't chastising. It's very common - not just in NJ - to blend the ideal mix for whatever depth you're doing.
     
  8. Doubler

    Doubler Loggerhead Turtle

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    Typical mix on Truk Odyssey is 30 to 24%.
     
  9. tracydr

    tracydr Divemaster

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    Thanks, guys. This is why I asked. Because I simply wanted to know what mix you would chose to dive at that depth, if given all available choices.
    i haven't taken any classes for Tech-diving yet, so I don't know much about gas mixes, beyond what PADI offers in their books and Encyclopedia.
    Plan to try attempt GUE-F next year sometime, but with a REC setup, most likely.
    i don't see my hubby and I doing tech dives anytime soon, unless next year's move takes us near a state with caves or wrecks. If that happens, will reevaluate the plan.
    I really do want to cave dive someday but oh, the money!
     
  10. Ragnar

    Ragnar Barracuda

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    I'm not surprised you have questions like this after being certified for Nitrox via Padi. Fundamentals will actually teach you more about best mix and standard mix. Do some self study and brush up on the math before doing the course using the Daltons diamond equation etc. All diving is somewhat technical and in my opinion all divers should acquire at least that level of knowledge which Padi most often fails to teach.
     
  11. RJP

    RJP PADI Pro

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    As long as we're hijacking this thread, let's go a step further and keep in mind that no one has ever been "nitrox certified by PADI" nor does PADI teach (or fail to teach) anything. INSTRUCTORS "teach" and INSTRUCTORS "certify." I learned about best mix, standard mixes, Dalton's diamond, etc from a PADI instructor. Hell, that stuff is even in the course materials.
     
  12. clownfishsydney

    clownfishsydney Manta Ray

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    Last Saturday in Sydney I dived the wreck of the SS Tuggerah which is a maximum of about 48 metres (160 feet) but averages about 45 metres (150 feet). I used 26%. As others have said, you can use "Nitrox" deeper than what you thought, you just need to get the right mix.
     
  13. Doubler

    Doubler Loggerhead Turtle

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    Why is 32% considered the standard when it does not take you to recreational depths?
     
  14. RJP

    RJP PADI Pro

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    MOD of EANx 32% at 1.6 P02 = 132fsw

    So, technically, 32% can get you to the bottom of recreational limits.

    That said, given a standard AL 80cf cylinder and the SAC of a standard recreational diver... you'd run out of gas long before you ran out of bottom time at 132fsw.

    At 1.4 PO2, MOD for 32% = 111fsw, which is perfect for the relatively standard "100ft or shallower" depth of 99.999999% of dives that recreational divers conduct.
     
  15. clownfishsydney

    clownfishsydney Manta Ray

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    You might run out of gas, not one of the people I dive with would run out of gas on such a dive.

    The bottom time for 132 feet (40 metres) has a bottom time of at least 9 or 10 minutes. If I did this dive within deco limits using my 88 cf aluminium tank I would come up with about 150 bar (say 2200 psi).

    On the dive I mentioned above last weekend, I averaged over 45 metres and did a 16.5 minute bottom time (2.5 minute descent). I was using a steel 12 litre tank (say 100 cf). I surfaced with about 90 bar (say 1300 psi), although I did breath 59% from 6 metres for about 8 minutes.

    Virtually everyone in our dive club could run out of bottom time at any depth (deeper than say 50 feet) before they would run out of air.
     
  16. scubadada

    scubadada Diver ScubaBoard Supporter

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    Hi I-169

    Your MOD is determined by the pO2 you're willing to dive at maximum depth. The oft quoted pO2 of 1.4 is reasonably conservative and yields a MOD of 132 feet with 28%, 111 feet with 32% and 95 feet with 36%. Some of us, at times, will dive a higher pO2. At a pO2 of 1.6, the MOD of 32% is 132 feet.

    Good diving, Craig
     
  17. RJP

    RJP PADI Pro

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    Do note that I referenced "the standard recreational diver" in my comments.

    According to V-Planner, I'd use 34cf of gas on a 10min no-deco dive to 130ft.

    I'd also never do a wreck dive to 130 on a single tank, irrespective of tank size.

    But we've now wandered too-far-afield from the OP's original question.
     

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