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Multilevel diving

Discussion in 'Ask Dr. Decompression' started by Nautilus, Aug 29, 2000.

  1. Nautilus

    Nautilus Guest

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    Hello fellow submariners:
    I've been investigating in the internet some information about multilevel diving without much luck. The only references to it are in the PADI instruction manuals. Also know that this is a touchy subject for many and would like to know more about it without relying on the PADI manuals.
    Are there any other sources about this matter elsewhere that any of you would like to share?
    Thanks and happy diving to all!
    Nautilus
     
  2. old_mike

    old_mike Nassau Grouper

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    wellll, a lot of folks are guilty (if there really is anything to be guilty about) of doing this, myself included.
    I try to avoid it, but when chasing mantas or a school of 'cuda, i have been known to bounce around. Off of cold, murky, current swept Southern Cal however, things are a lot closer to the edge of my comfort zone so i make it a hard fast policy to avoid multi-level dives, photos be darned.
    i too am interested in any scuttlebutt (physiological research or otherwise) on the subject.
     
  3. DVG

    DVG Guest

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    The dive tables assume you are doing a perfectly square dive, i.e., go straight down, stay at one depth and come straight back up. That is a safety feature but it is not a true profile of most dives, at least not my dives. When I finally got a computer and I actually saw the profile I dove, I realized the impracticality of square assumptions and never looked back. I just make sure that whatever level change I am doing once I descend, is done very slowly and I dont worry about it. I'd like to hear from others on this point and I may have to eat my words (but I probably wont change my habits). As far as reading about MLD try searching DAN's site.

    Dive Safe
     
  4. Moondiver

    Moondiver Guest

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    I have to agree with DVG - the bottoms of oceans, lakes, etc aren't one level, so no dive is going to stay at one depth for its duration. The best advice is still "Plan your dive and dive your Plan," and ascend slowly.
    Safe diving!
     
  5. Beachman

    Beachman Nassau Grouper

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    ....the issue of planning MLD's seems pretty well past. Tables, the Wheel, and just your computer countdown for a square dive are all appropriate pre-dive planning (you never know when something you're depending on craps out down there).

    There have been several articles in the past couple of months indicating that the old rules of "deepest first" and "first dive, deepest dive" have no physiological basis. Rather, they relate to issues of safety in pre-computer days.

    If it sounds like I'm taking computers for granted, I guess I am....but frankly, I feel they are as essential as a BC, reg, weights, etc. Sort of like when I was in engineering school years ago and we all used slide rules. Anybody know what a slide rule is today?

    DSAO
     
  6. old_mike

    old_mike Nassau Grouper

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    i actually have a few old slide rules that date back to the 1970s when all the defense contractors were in the LA area!
    regarding MLDs though, i have a habit or running into situations off of So Cal or other areas where i really am leery of deviating from a rigid plan: such as the local oil rigs, where the bottom is 700 feet down and we are in blue water, or off of steep walls where the bottom is 200 feet to 6000 feet and we might descend to say, 150 looking for hammerheads. In a shallow kelp forest or coral reef, i don't worry as much unless it's the 4th or 5th dive of the day and my N-loading is still 2/3 to the yellow!
     

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