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  1. #1
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    Default Lost buoyancy incident

    Thought I would relay an incident that happened to me last Thursday in the event it may help someone else not make the same mistake that I made.

    I had the chance to make a solo dive recently (my first) at JB and it was one of my best dives ever. So, on a trip to the Florida Panhandle last week, I decided to make another solo dive at JB. My plan was to go straight down the gold line to thirds and then have a relaxing float back.

    Normally, I dive dry but my dry suit is a back zip and I cannot zip it without assistance. So, I dove with my wetsuit. As a result, I did not have any buoyancy back up. (see where this is going?) To add to this, I recently started diving side mount. When I bought my SM wing, I switched the location of the dump valve and the inflator so that that the dump valve is on my shoulder. The cord to the dump valve had been lengthened, threaded thru a flexible plastic tube which is zip tied to the inside of one of the Velcro flaps on the left shoulder. Recently, I replaced the cord with a longer piece to make it a little easier to reach. However, as I was gearing up when I noticed had forgotten to finish the repair. I had not yet threaded the cord thru the tubing and re-attached the knob. No problem I thought. The cord was long enough for me to loop around the flap and tie it which I did. In the water, I tested the inflator and then pulled the dump cord to let air out. I checked my air, regs, lights, etc. Everything worked fine. My 80 stage had 2800 and my 95s had 3500 each. My plan was to dive the stage to ½ plus 200 and the main bottles to 2400 or 2500.

    I tied my reel at the entrance, dropped an O2 bottle in the cavern, and then ran my reel to the main line. I breathed on the stage to somewhere before the first breakdown before switching to my right bottle. Close to the second breakdown, I switched to my left bottle. At the second breakdown, I dropped my stage on the main line. I then started to swim up and over the breakdown. At the top of the breakdown, I seemed a little light so I grabbed the dump line and let some air out of my wing. Shortly afterwards, I began to hear air which seemed strange. I knew it was not my tanks since they were on my side. I thought maybe it was my exhaust on the ceiling which was right above me.

    I kept going and started my descent down the back of the breakdown. I was descending fast and started added air to my wing but I kept sinking. I now realized the air I heard was air escaping from my wing’s dump valve. I reached up and tugged at the cord thinking that something was caught in the dump valve but to no avail. I realized after the dive that my cord probably got caught in the Velcro when I tugged on it and would not allow the valve to close. At this time, I had a sinking feeling as I realized I would be exiting with two steel tanks which no air in my wing. I would basically be crawling on the floor. I climbed up, over, and down the second breakdown using a combination pull and glide and a frog kick.

    When I reached my stage, I tried to add air again but it immediately went out the dump valve. When I saw the stage, my immediate thought was will the stage be more trouble than it is worth? I quickly decide more air was probably a good thing and grabbed my stage. From the second to the first breakdown, it was easy to pull and glide on the floor but I was exerting myself and trying to control my breathing. While only several hundred feet, the first breakdown was a welcomed sight the first breakdown, I check my gauges. I cannot remember how much air was in my left bottle but I still had 3000 in my right tank and 1600 in my stage. At this time I knew I had more than enough air to get back.

    From the first breakdown to the chimney, there were spots with not a lot of limestone so I did my best to bounce and swim from hard spot to hard spot until I got to the chimney. At the chimney, I was breathing hard so I stopped for a minute or so to catch my breath. At this time I think I checked my gauge again and saw 2000 in my bottle and switched to my right bottle. I then pulled and kicked my way to the top. At the top of the chimney, I moved to the center of the cave when I saw natural light as it provided a more level exit. Thinking that I would be back on Sunday with a buddy, I left my reel. At the bottom of the cavern entrance, I tried again to inflate my wing and it held – go figure. At this time, I looked back at my line and did not like the way it looked so I retrieved it from the permanent line. Anticipating a return in three days, I tied it off on a rock at about 35 feet. I completed my dive with a safety stop.

    I learned several valuable lessons. I had redundancy for gas, lights, safety reels, cutting device but not for buoyancy. This was certainly part of my training but I had allowed myself to be lax in this area especially diving with steel tanks. The lesson learned is to dive dry or get a dual bladder. The second thing I did wrong was to not properly repair the dump cord which allowed the cord to get caught. The lesson learned is not to rig any repairs. It needs to be completed properly.

    I was really thankful to have this happen in JB where most of the floor is hard and relatively silt free. It could have been a lot worse if I had been in Twin or Hole in the Wall. Also, I was fortunate to have had the issue at 800 feet rather than at 1500 feet. When I exited the water, I still had a lot of air – 2000 and 2100 in my 95s and 1600 in the stage. My air consumption rate was about 15% higher than normal which would be about 30% higher on the return. Had I exited from 1000 or 1500, I am sure I would have exceeded that.

    If anyone has any questions, I will be glad to answer them. Or if anyone has comments related to anything different that could have been done when realizing there was a problem, let me know.

    Safe diving,

    Sandy Robinson

  2. #2
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    Default

    Thanks for the post. Not many people post here, and armchair cavediving is always easy to do from the computer desk.

    Since you asked for other thoughts, I'll throw a couple in here.

    1. A possible solution in JB with the hard floor in so many places could have allowed one to take the gear off and troubleshoot the issue in a short time with little cave/vis disruption. Was this a thought you had?

    2. Did you attempt to see if the wing held buoyancy while in certain trim positions? This may have assisted you with the exit allowing for some lift rather then none. (Also, did you try putting air in the wetsuit for at least a couple of lbs of lift?

    Just some thoughts from first glance. Thanks again for posting this for others to review and throw critiques out. Glad you made it back safe.

    Joe


    Quote Originally Posted by Richard Pyle
    "After my first 10 hours on a rebreather, I was a real expert. Another 40 hours of dive time later, I considered myself a novice. When I had completed about 100 hours of rebreather diving, I realized I was only just a beginner."

  3. #3
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    Default

    Thanks for posting this. I just had a similar incident in Twin about a week and a half ago. Fortunately, I only drive dry unless diving really small cave where buoyancy isn't an issue because I'm wedged between the ceiling and the floor. My incident involved the exhaust being stuck open because of a piece of limestone that fell in there. I was in a passage that isn't dived all that often and there was a lot of percolation. A piece of limestone must have fallen into the exhaust when I was exhausting air. I didn't realize this until I was back at my jump spool. The passage requires a short vertical ascent in which you have to go vertical. I did this and hit the inflator to add a little air and heard a bunch of air escaping from behind me. I hit it again and heard the same thing. I immediately hit my dry suit inflator but because I was vertical, most of the air escaped around my neck seal. I finally managed to get myself horizontal and get neutral again with my dry suit. I took the exhaust apart once back to my boat and saw the small piece of limestone. I'm planning on getting some screening to put in there above the spring to keep this from happening again.


    As for your dive plan, I don't understand diving 1/2 + 200 on your stage and 1/3s on your sidemount cylinders. You realize this means you are violating 1/3s, right? If you dive 1/2 + 200 you need to cut back on how much you breathe from your sidemount cylinders so you are diving 1/3s of all your gas.

    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

  4. #4
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    Joe

    Surely taking tanks off would lead to excessive buoyancy, possibly losing a reg and drowning? Not sure that's what I would try.

    Andrew Ainslie

    Almost extinct cave diver

  5. #5
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    Quote Originally Posted by aainslie View Post
    Joe

    Surely taking tanks off would lead to excessive buoyancy, possibly losing a reg and drowning? Not sure that's what I would try.
    In a wetsuit? Come on. Please tell me you did this exercise in OW class...

    Joe


    Quote Originally Posted by Richard Pyle
    "After my first 10 hours on a rebreather, I was a real expert. Another 40 hours of dive time later, I considered myself a novice. When I had completed about 100 hours of rebreather diving, I realized I was only just a beginner."

  6. #6
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    Default

    Quote Originally Posted by RN View Post
    because I was vertical, most of the air escaped around my neck seal.
    Do you do the "reverse turtleneck" thing on your neck seal?

    Whoever said money can't buy love never bought a puppy.

  7. #7
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    Quote Originally Posted by Slüdge View Post
    Do you do the "reverse turtleneck" thing on your neck seal?
    I have a Black Ice and it's a neoprene neck seal, so I have to. The problem is I have about 200 dives on the suit so the neck seal has stretched. I just installed a latex neck seal in the suit yesterday.

    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

  8. #8

    Default

    I had a simular thing happen a few months ago. I was prepping for a deep dive and was going to use a new wing. So I did a shallow dive in a local quarry with all my tanks and bottles. The new wing has a dump on the right shoulder, where my normal wing doesnt. I didnt give it much thought until I noticed a lot of air escaping it. What had happened was the pull cord for the dump got stuck under my back plate and it was contantly cracking it after putting in so much air, so instead of being a 60# wing, it only had about half of that before the dump opened. I remembered to check it before the deep dive the next week though!

    Thanks for posting your incident.


    Scott


  9. #9
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    Default

    Thanks for posting this. I generally dive dry, but I will cave dive wet with a lift bag on very hot days.


  10. #10
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    Quote Originally Posted by Tegg View Post
    In a wetsuit? Come on. Please tell me you did this exercise in OW class...
    Yeah, I suppose I'm showing my memory loss here. Haven't dived wet in fresh water for years.

    Andrew Ainslie

    Almost extinct cave diver


 

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