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  1. #11
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    For measuring the spring flow- make as accurate map as you can of a flat cross section of the entrance and figure the area. Measure the velocity with a sponge floating in the water column along a known distance. (Let a survey tape with a little float on the end down into the passage 10 or 20 feet, then release the sponge, time how long it takes to hit the end of the tape) There is feet per minute x your area of the entrance ft2. = ft3/min. Obviously this is rough as flow moves at different speeds in different areas of the entrance, but this will give you a rough idea without having to capture the flow or use a $10k instrument.


  2. #12
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    For large springs, use a tape measure to determine the average stream width and depth, and multiply this cross-sectional area by the current speed. To estimate the current speed, toss a floating object - an orange is recommended - into the spring and clock the time it takes to travel a known distance. If your spring averages 2 feet wide x 1 foot deep (an area of 2 square feet) and the current speed is 3 feet per second (the orange travels 30 feet downstream in 10 seconds), then a rough estimate of your spring flow is 6 cubic feet per second (area in square feet times speed in feet per second equals cubic feet per second) or 2,700 gallons per minute (1 cubic foot per second [cfs] = 450 gpm).
    This is fairly simple and commonly used. Use the spring run,but if you have several springs venting into the run,then you'll have to isolate the specific spring to get an accurate measurement. Not too sure about using something very buoyant because it can be effected by the wind.

    "Not all change is improvement...but all improvement is change" Donald Berwick

  3. #13

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    Quote Originally Posted by RN View Post
    Go in with rope and I would even recommend tying loops you can fit your hands into about every meter as well as wearing gloves. Maybe the flow isn't that bad per Florida standards, but the way you're making it sound I would be very concerned about diving into that siphon. And I'm used to flow.
    Thanks that's very reassuring especially coming from an experienced Florida "flow" diver..lol
    Without exaggeration the flow in to that tunnel was the kind you would have to pull yourself out of and rope sounds like the way to go, we will push the upstream first, I chickened out and my feminine side took over at that point..lol then Cristian took the reel and pointed out the upstream (duhh) I had not seen and we had to pull ourselves up that tunnel, no way swimming works.
    The siphon is a scary thought but aside form that I really like diving in flow, a totally different kind of experience, we did I think 52mins in and less that 10 out.

    Dominican Republic Speleological Society
    http://dr-ss.com
    Aquavista Films LLC.
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  4. #14
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    May 2006
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    North Florida
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    Plan your dive in reverse. I wouldn't allow the flow to take me in. I would use the rope to let myself in. 1/5 the time in is a huge difference in time. Plan your gas very carefully.

    Rob Neto
    Chipola Divers, LLC
    Check out my new book - Sidemount Diving - An Almost Comprehensive Guide
    "Survival depends on being able to suppress anxiety and replace it with calm, clear, quick and correct reasoning..." -Sheck Exley

  5. #15

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    Quote Originally Posted by Kelly Jessop View Post
    This is fairly simple and commonly used. Use the spring run,but if you have several springs venting into the run,then you'll have to isolate the specific spring to get an accurate measurement. Not too sure about using something very buoyant because it can be effected by the wind.
    On the surface, but it sounds like they are measuring flow from a side passage underwater......

    9/11....... I remember .........

  6. #16
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    Nov 2004
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    In a Virgin Cave in Dominican Republic :D
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    yes I think we can measure more accurate underwater, in the surface expands really quick to the ocean. something very floaty wont work, but well at the end is what I thought at the beginning, measure surface and flow, I thought there could be some more tips or something I was not thinking about.

    Phill female side was really funny, I told him next time he can hold my hand. The flow is strong but not that bad, is like the restriction going in the ear at ginnie(about a year ago was about 10 times what is now and we couldn't go in), maybe a rope would be good for a first look in the downstream, but hanging from the rocks will work too.

    Cristian Pittaro
    www.neptunoworld.com
    and don't forget to check out my MiniSpools
    http://www.dr-ss.com Dominican Republic Speleological Society
    http://la-hispaniola.com Free maps for Dominican Republic and Haiti for Garmin GPS's

  7. #17
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    Remember if the downstream passage gets smaller the flow will get stronger. And if you get into a restriction the head of water will probably trap you there.


  8. #18

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    Quote Originally Posted by rjack View Post
    Remember if the downstream passage gets smaller the flow will get stronger. And if you get into a restriction the head of water will probably trap you there.
    that would really suck, and there is no way I am going into a restriction in a siphon in the first place, my feminine side says "no!" I think a rope is a very good idea, we are talking about flow you cannot swim against and sucking you into the cave to who knows were.

    Dominican Republic Speleological Society
    http://dr-ss.com
    Aquavista Films LLC.
    http://www.aquavistafilms.com

  9. #19
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    Any chance there's a lower flow season?


  10. #20

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    The summer here has way less long periods of rain so I guess it is now

    Dominican Republic Speleological Society
    http://dr-ss.com
    Aquavista Films LLC.
    http://www.aquavistafilms.com


 

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