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how deep max. when diving solo?

Discussion in 'Solo Divers' started by Taliena, May 5, 2014.

  1. Kevrumbo

    Kevrumbo Banned

    # of Dives: 1,000 - 2,499
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    [
    Those are fine gas plans too . . .again you can make the arbitrary parameters (ascent rates, safety stops, breathing gas margin etc) as conservative as post #92, or as your calculations above. The point is to do the calculations, and find the proper amount of gas needed to fit your preferred ascent rate profile and emergency/contingency breathing rate at depth & on ascent, for yourself as a Solo Diver or as part of a buddy team.

    When I dive OW Solo, I use conventional double manifolded Backmount AL80's or Z-system Sidemount double AL80's: having the peace of mind with more than enough breathing gas for me diving Solo is more important than the inconvenience & extra burden of carrying a larger redundant back-up gas supply.
     
    Last edited: Jun 11, 2015
  2. DaleC

    DaleC Solo Diver

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    I edited my prior calculations because I calculated atm's at 30 instead of 33' and to round up. The values remain basically the same.

    We were taught in Fundies to learn the calculations so we understood the theory behind the values and then we created a quick reference guide for varying depths. Then using tank factors we could quickly calculate psi values for various tanks to use as reserve. That was a very useful part of the course for me.

    I'm not really a fan of the 30'/minute - min deco concept, though I understand it. I would rather move shallow faster and do a longer SS there knowing I was within cesa range, than to ascend slowly having already experienced one failure. Seeing as I am solo I do not have a redundant redundant airsource.
     
  3. dumpsterDiver

    dumpsterDiver Banned

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    Since we are way off from the original discussion of: how deep solo??

    A video I made of ascending from 60 with a 13 cu-ft pony - It seems to show there is plenty of air for an ascent (from 60).


    [video=youtube;r-L9extLDZQ]https://www.youtube.com/watch?v=r-L9extLDZQ[/video]
     
  4. jnowak100

    jnowak100 Tech Instructor

    # of Dives: 500 - 999
    Location: Philadelphia, PA
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    Dive to the limits of your personal experience, training, gear, site, environment, and comfort level, but dont push them. solo should be easy and comfortable dives, if you are really pushing your limits or beyond a buddy is advised.
    so,
    0 = keep the dive plan simple for each dive
    1 = you are alone, starting and ending the dive alone you rely on your own skills and gear
    1 1/2 = gas management, adequate and ample gas reserves for the dive
    2 = redundant gas and all life support gear,
    3 = respect the general rules and your own standards dont cut corners
    4 = respect the limits and risks of depth, time, site conditions
    high 5 = have fun
     
  5. Kevrumbo

    Kevrumbo Banned

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    Here's an interesting claim:
    This diver should think again --keep the 13cf bottle and go no deeper than 30m/100'. . .
     
  6. BCSGratefulDiver

    BCSGratefulDiver Mental toss flycoon ScubaBoard Supporter

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    I agree with Kevin. Do that math again. If your SAC rate is 1.0 cf/min (not uncommon for a diver experiencing the stress of an OOA), you'll suck down about 4 CF that first minute going from 130 to 70 (average depth 100 feet/4 ATA). You'll run out of air before you reach 40 feet and have to bolt to the surface from there.

    One thing you forgot to remember is that your consumption increases proportional to depth, and your SAC is calculated at surface pressure (1 ATA). At 1.0 cf/min you'll need roughly 8.5 cf to make a direct ascent (skipping the safety stop, which isn't recommended from a 130-foot ascent).

    Suggest you re-think your bail-out strategy, and follow Kevin's advice about keeping the 13 CF bottle. For that matter, if you're basing your bail-out on running OOA at 130 feet, suggest you re-think your whole dive profile, and put more effort into your dive plan before deciding to go that deep ... this might be helpful ... NWGratefulDiver.com

    ... Bob (Grateful Diver)
     
  7. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

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    It is certainly possible to get to the surface from 130 ft b on a 6 cut bottle. The average depth is 65 ft so the average Ata is 3. If you go at 60 fpm it will take 130 s. So that means an average air consumption rate of 6/130 >> 2.8 cuft/min, thus a SAC of 2.8/3 = 0.9. Of course, you can't get access to the entire 6 cuft because of the way regulators work, and you shouldn't go 60 fpm for the last half of the trip, and a safety stop would be nice, and you better not be stressed. So, it can certainly be done, but it is certainly not a good idea.
     
  8. Tigerman

    Tigerman Solo Diver

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    Hey, if were going up at a fast rate and skipping the safety stop anyways, you don't really need gas the last 60 ft anyways, as you can just CESA it... (Yeah, still not my favourite plan)
     
  9. Kevrumbo

    Kevrumbo Banned

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    Of course, if you can maintain a SAC rate of 0.5 cuft/min, you can make it to the surface per the parameters posted above by diver Kharon.

    More power to Kharon if this diver can keep that nominal SAC rate to ascend & surface from 130' on an AL6 pony bottle.
     
  10. Germie

    Germie Cave Instructor

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    I did in october a solo cavedive of 3 hours with a maximum depth of 76m. Approx 1050m from entrance in the cave. On ccr.
     
    Last edited: Dec 21, 2015
    northernone likes this.

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