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Unexpected rapid ascent

Discussion in 'Advanced Scuba Discussions' started by ladyfishdvr, May 12, 2014.

  1. ladyfishdvr

    ladyfishdvr Nassau Grouper

    # of Dives: 50 - 99
    Location: Rochester NY USA
    160
    79
    28
    I had an unusual experience yesterday while diving and I am trying to sort out what may have happened.

    I was diving with 3 people at Dutch Springs and we were going to the deep hole. We surface swam out to the army truck then dropped down to 77 feet. Then headed towards the deep hole. My buddy is an experienced diver who I trust, and because I was diving an AL80 with 2800 psi he gave me his pony bottle. He had doubles. First time I ever dove with one so he ran through the details. We were leading and the other two guys were behind us. I started hearing air but my reg was not free flowing and it was sporadic then it stopped, so I grabbed my gauge to monitor and I had dropped from 2800 to 2000 in 8 minutes. So as we approached the ledge to the drop off my buddy (who had just checked on me) was just a tiny bit ahead of me and I was thinking I will stay up here and hover instead of going down until I figure this out, then suddenly I started going up. I realized my BC had completely inflated and then my regulator went into freeflow. I immediately grabbed the pony reg so I knew I had a solid air source. I did try to slow my ascent by heading down and dumping air but the bc kept filling and I popped up on the surface.

    I remember thinking, "Well that was bad". I felt ok so I figured I would hang out where the bubbles were coming up until my buddy came looking and was thinking "Gee I hope he does not come up too fast looking for me". He did come up fairly quickly and looking very concerned. When he realized I was not visible he knew I was in trouble because I am always close and visible when we dive.

    I talked to a friend when I got home and he advised to get my reg checked out. I dive a conshelf 21. Possibly it froze up and came out the bc hose first then the reg.

    So I am thinking, I have never heard of a freeflow happening like that, has anyone else? And maybe I need to update my regulator to a closed system if I want to dive colder water.

    I had my gopro running and have a video and it is amazing how fast two people can separate underwater when they are going in opposite directions. It really just took seconds.
     
    Tricia likes this.
  2. Phil_C

    Phil_C Instructor, Scuba Staff Member

    # of Dives: 1,000 - 2,499
    Location: UK, Middle East, Cyprus
    934
    416
    63
    I'm not sure what temperature the water was but you are unlikely to have had problems with both the BC inflator AND the second stage as a result of temperature.

    I am only guessing but it sounds like you have had a permanent slow leak on the inflator hose into the BCD through out the dive which is why you could hear air (though why it should seem to start and stop I don't know), I would guess also that you may have been overweighted, especially if you had added a pony without changing weights and this is why you ended up with a full bcd on the surface but hadn't had a really sudden runaway ascent.

    Possibly when you reached the point with the bcd inflation that you could no longer keep your buoyancy under control and started to go up, you were stressed and by then over breathing and that caused a regulator free flow.

    So first I would be inclined to get the BC inflator and shrader valve on the inflator hose checked out, before going to blame the regulator itself. Your buoyancy problem had manifested itself before the regulator free flow, and you had a full BC which to me would point to the BC hose and connector. I suspect the free flow was additional as a result of the 'stressful' dive.

    Again as I said I am only guessing, but that seems more likely than something causing both your BCD inflator and second stage to malfunction at the same time. If you are really bothered then of course you could get the BC inflator and the regulator checked out.

    Dive safe

    Phil.
     
  3. Jim Lapenta

    Jim Lapenta Dive Shop

    # of Dives: 500 - 999
    Location: Canonsburg, Pa
    16,920
    8,700
    113
    bc inflator leaking and/or the schrader valve in the lp hose leaking through. Dutch Springs is cold water. I'd expect the temps deep/below the thermocline to be in the 40's still. What happened was your first stage froze up and went into freeflow due to the adibiatic cooling effect of all that air flowing unrestricted through it. I would also have the IP checked as a precaution. Nice move recovering like you did. More than a few people have panicked and died as a result of what happened to you. Are you diving a sealed cold water reg and was the IP.correct before you started? On a dive like that this time of year that should be in your pre dive check list.
    Sent from my DROID X2 using Tapatalk 2
     
  4. ladyfishdvr

    ladyfishdvr Nassau Grouper

    # of Dives: 50 - 99
    Location: Rochester NY USA
    160
    79
    28
    Funny you say that but I listened to my breathing on the video and it was fairly normal the entire dive down and up. As I descended I was adding air to the bc to slow up, so it was a controlled descent. I went slow because I need extra time to equalize. The water was 41 F at the bottom and if overweighted it was only by a slight bit. My first dive I tossed a few rocks in my bc cause I was a bit under weight. When we got to the bottom I was actually annoyed because the two other divers were sitting on the bottom and when we came down we stopped at a 5 foot hover fairly easily.

    I also thought it was the bc first as well, and am going to have that checked also. It's less than a year old but I want to make sure its also safe to dive again.

    ---------- Post added May 12th, 2014 at 08:38 AM ----------

    Jim, thats what SeaCobra suggested as well. I just had the reg serviced for the year but I need to have the IP checked now. Its not a sealed reg. Its an antique conshelf 21. The water was 41 at the bottom.

    I am thinking I need a sealed cold water reg because I sort of like diving chilly.

    I don't normally panic, because its counterproductive.
     
  5. Malpaso

    Malpaso Solo Diver

    # of Dives: 200 - 499
    Location: MA/CT
    676
    200
    43
    I have a question about what could have been done, not what caused the problem. If there was enough time to do so, would disconnecting the BC inflator hose have helped?
     
  6. AfterDark

    AfterDark Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Rhode Island, USA
    9,381
    5,567
    113
    What side was the pony on? Is there a chance that the position of the pony caused it to push against the inflator button? Did you change the position of your arms causing the pony to shift? This never happened to you before and it was the 1st time using a pony? Just some thoughts.
     
  7. ladyfishdvr

    ladyfishdvr Nassau Grouper

    # of Dives: 50 - 99
    Location: Rochester NY USA
    160
    79
    28
    By the time I realized the bc was causing my ascent it was full. If I had realized that earlier I could have disconnected it and dumped air to stop my ascent but that did not click in my brain until I felt the squeeze on my ribs from the bc. and thats the moment my regulator began to free flow and I switched to the pony. I did not think to disconnect the BC hose, and I should have.

    On the video it took 60 seconds from start to finish so I had little time to react.

    ---------- Post added May 12th, 2014 at 10:05 AM ----------

    The pony was on the left and high. I had my hand on the air2 the entire time because the pony was there. It was not pressing on the inflator valve. I am happy I had the pony and plan to get my own for future dives.
     
  8. Diver0001

    Diver0001 Instructor, Scuba

    0
    34
    0
    Posting the video might help us give you a diagnosis of what happened.

    The most obvious thing to suspect is that the 1st stage of the regulator hung "open", whether due to freezing or some other thing and therefore would have been essentially delivering unregulated tank pressure straight to your low-pressure ports (2nd stages and inflator hose). That would certainly cause your 2nd stages to free flow and *may* have caused your BCD inflator to free flow as well.

    One of the things that could cause this could be the lack of environmental sealing as Jim mentioned. Another possible cause could be water inside the first stage from, for example, rinsing. What do you normally do to rinse your reg after diving?

    R..
     
  9. ladyfishdvr

    ladyfishdvr Nassau Grouper

    # of Dives: 50 - 99
    Location: Rochester NY USA
    160
    79
    28
    My last dive was two weeks prior to this one. I rinse in water and I am diving fresh water. It was my second dive of the day.
     
  10. j yaeger

    j yaeger PADI Pro

    # of Dives:
    Location: Canton, New York, United States
    1,501
    310
    0
    cold water for that old conshelf
    jim said it correctly-1st stage icing up making high ip
    things cascade from there with 2nd stages and inflators freeflowing
    good lessons learned and good outcome!
    pull the corrugated hose!!!!!
    let the air out while disconnecting the lp hose-good practice skill!
    have fun
    yaeg
     

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