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Nitrox benefits for Cozumel diving

Discussion in 'Cozumel' started by tracydr, Jul 23, 2013.

  1. tracydr

    tracydr Divemaster

    # of Dives: 500 - 999
    Location: North Carolina, 3 miles from South Carolina
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    A ScubaBoard Staff Message...

    This side discussion about nitrox has been split from a thread discussing 2 tank morning dives in Cozumel. Marg, SB Senior Moderator


    Why?You're increasing your nitrogen loading, causing you to have shorter bottom times and less safety than if you dove nitrox for all your dives. Change the mix for the dive to the appropriate percentage but why dive air?

    ---------- Post added July 23rd, 2013 at 09:15 AM ----------

    I doubt its an age thing. I'm 48, my husband 53. We've dived with 70 year olds that we can't keep up with. Heck, I'd say a great percentage technical divers are in their 50s or older.
     
    Last edited by a moderator: Jul 23, 2013
  2. supergaijin

    supergaijin Dive Shop

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    I think some people view Nitrox on subsequent dives as being akin to a sort of accelerated decompression. IMO it's best to use you Nitrox (if you only have one tank) on your first dive to reduce the Nitrogen in the first place. Of course some first dives are too deep for standard mixes like EAN32.
     
    tracydr likes this.
  3. tracydr

    tracydr Divemaster

    # of Dives: 500 - 999
    Location: North Carolina, 3 miles from South Carolina
    2,730
    743
    Why doesn't she get certified? It's a non-diving class for many agencies so if she doesn't want to dive locally ( a shame to miss S.CA diving,but) she can still take the class. And, many resorts offer 1 hour nitrox classes. Although, I wonder how good those classes actually are.
    I can only see not diving nitrox if nitrox is not available, like when we dive with Truth Aquatics.
    You can easily get a lower mix for those wall dives ( are you really diving deeper than 130?) and I don't believe down currents are nearly as much of a boogie man as some make it seem. And yes, I've experienced down currents. Believe me, Galapegos and Africa have down currents.

    ---------- Post added July 23rd, 2013 at 09:24 AM ----------

    I love getting up early on vacation. Although it often difficult because we almost always do night dives which keep us out late.

    ---------- Post added July 23rd, 2013 at 09:27 AM ----------

    This is the reason I haven't been to Coz in so long. I think 1999 or 2000 was my last trip. I look for value per dive, among other things for my trip choices.

    ---------- Post added July 23rd, 2013 at 09:32 AM ----------

    For Bonaire, you have to travel on Saturday out of Houston and stay a week. At least, that's how I've found the best deals. There is a weekly flight from Houston which is reasonable, or was a couple of years ago. It's a challenge to get to Bonaire, that's for sure. But the value once you get there is very high. We never use a boat and dive 4-5 tanks a day. Usually a rental truck and unlimited nitrox is included in our package, even when renting privately owned homes.
     
  4. mstevens

    mstevens Toadfish. Splendid is implied but not guaranteed. ScubaBoard Supporter

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    In Cozumel? If that's what you're saying, I disagree.

    Easily. The exit for one popular swim-through dive often results in a maximum depth greater than 130 fsw, and that is without any sort of safety margin for current or whatever.

    Value per dive, or price per dive? Those are very different things.
     
  5. tracydr

    tracydr Divemaster

    # of Dives: 500 - 999
    Location: North Carolina, 3 miles from South Carolina
    2,730
    743
    Mstevens- I realize there is a dive with a swim through at deeper than 130. We won't even discuss if this appropriate on a single tank for recreational divers. But, if you're diving a wall, you dive as deep or shallow as you want.
    As far as mixes, if diving to 130 is standard, then it would be smart for the air filling station to offer a 28% mix, which is a standard mix in many parts of the US.
    How many divers get bent diving air in Cozumel each day? How many divers diving nitrox? I say nitrox is far safer and if the dive-ops on Cozumel were really looking out for the safety of their divers they would encourage the use of nitrox with the appropriate MOD for each dive. From the sounds of it, people are riding the computers right up to NDLs commonly while diving on air just so that they can go deep when ideally, 28% would be better on those deep dives. It's those deeper dives 90-130 feet that are more likely to get the recreational diver into trouble with DCS.
    Maybe its just because I'm "old" but my old bones really prefer the added safety and added bottom time of nitrox, no matter where I dive. It bothers me that our favorite boat for the Channel Islands doesn't offer nitrox and I certainly hope they change soon.
    I'm 48 years old and suffering from osteonecrosis in at least 5 joints. Although it was probably mostly caused by a large dose of steroids, I wish that somebody had stressed the importance of nitrox to me back about 17 years ago.most of my diving, until a few years ago was air. Maybe, just maybe I would have healthy bones if I'd dived nitrox for those early years of my dive career when I just thought it was an added expense or only needed if I wanted to spend more time on the bottom.
     
  6. Karibelle

    Karibelle IDC Staff Instructor

    1,216
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    Want me to fix that? ;-)
     
  7. robint

    robint Contributor

    # of Dives: 500 - 999
    Location: Albuquerque, NM
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    Deeper isn't always better. I find all the reefs in Cozumel are most colorful and interesting from 50-80'. From 80-100' there is still alot of coral, but not worth going there if it is just the same as shallower. And yes, I always dive NITROX. SCC pumps 32% or 36%, you pick what you want. They have their own compressor for air but I think they get the nitrox delivered as you have to order the day before.

    I have zero interest in Devil's Throat. I have done cenotes, I have done blue holes in Palau. I don't do dives just to say I have done them. Give me a colorful reef covered in coral, sea fans, sponges, and fishlife and I am happy.
     
  8. Christi

    Christi PADI MSDT/Dive op owner ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: Cozumel, MX
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    Sorry to add to the thread hyjack - but this is important.


    Tracy, no offense intended here, but by your own admission, you haven't been to Cozumel in over a decade. With that said, it would be a fair and accurate assessment to say that you are not familiar with Cozumel or operating practices here. Nitrox IS readily available and different mixes CAN in fact be ordered, but not always guaranteed since there is only one fill station that fills nitrox other than the few operations on the island with their own compressors.

    Another misnomer however is that you cannot get bent diving nitrox - this is completely false. And furthermore, nitrox is ONLY "safer" than air if diving nitrox within air limitations - otherwise, diving nitrox to nitrox limits is exactly the same thing as diving air to air limits - you are still loading nitrogen when diving nitrox! So while your "old bones really prefer the added safety and added bottom time of nitrox..." - you're actually not diving any safer than someone diving air on an air profile.

    I've always taught it this way to my nitrox students, it is logical after all - but this was confirmed by 3 different hyperbaric doctors and a seasoned hyperbaric technician during an open house given at our chamber here just last week - in fact, this very question came up.

    There is also no proven correlation that diving deep gives one a higher probability of getting bent. The first atmosphere is the critical part of the dive - and that 10 - 15 stop is more important than many believe. This is the depth that studies have proven the most efficient and effective off gassing happens. This was also discussed in the open house several of us attended.

    I'll add, that I was diving nitrox in 2011 when I got bent with very conservative profiles, definitely within air NDL's. So it's VERY possible to get bent even when diving nitrox. I am also not sure how you can argue that nitrox will help you have healthier bones.
     
    Chuckitall, lindenbruce, D_B and 2 others like this.
  9. blue steal

    blue steal Solo Diver

    # of Dives: 500 - 999
    Location: Southern California/Redondo Beach area
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    I love diving nitrox in coz for that extra BT, 32 on the 1st and 36 on the shallower 2nd dive.
     
    in too deep likes this.
  10. Mossman

    Mossman Solo Diver

    # of Dives: 500 - 999
    Location: SoCal
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    The fact is, it is a lot easier to reach NDLs on air than on nitrox. The average air diver in Cozumel will likely be approaching NDLs more more closely that the average nitrox diver, especially if diving in a group of air divers where the profile will be tailored to air limits. Therefore, the nitrox divers will be absorbing less nitrogen.

    Also, as you say, the 10-15' stop provides that more efficient off-gassing. Don't you believe that the offgassing is even more efficient and effective on nitrox than on air? 32% might not be the best deco gas, but it sure beats offgassing on 21%. For this reason, diving nitrox on nitrox tables is safer than diving air on air tables, provided one does a "safety" stop and reaps the benefit of offgassing on a higher ppO2.
     
    tracydr likes this.

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