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Sharing air to extend bottom time

Discussion in 'Basic Scuba Discussions' started by t4e, May 22, 2012.

  1. t4e

    t4e Regular of the Pub

    # of Dives: 100 - 199
    Location: Burlington Ontario
    727
    231
    43
    We are in mostly sunny and somewhat rainy Riviera Maya for a week.
    Of course we booked some diving during this time.
    Being new divers we opted to hire a personal DM.
    First day comes along and I had trouble equalizing my ears so not wanting to waste too much time i decided to head back on the boat and at least let my husband go ahead and enjoy the dive.
    Thinking back now i think was more of a psychological issue, since the rough seas made me quite uncomfortable even on the way to the dive site but more so once i jumped in the water.
    Next day was all nice and calm and we had a good dive at 11.30.
    On the way back we decided to stick around and do one more at 2.30, on which just before the dive he asked us if we are OK if there is one more person other than us two.
    The DM was great, the briefing i felt was adequate.
    The plan was to let him know when we are on 700psi and we would be heading up to our safety stop.
    On the 11.30 dive all worked according to plan, once we motioned that we are on 700psi he deployed the sausage, which tbh i thought it definitely needed some viagra, and we made our way up.
    Second dive was a different story.
    700psi come along and we motioned to him, at this point i am expecting to see him reach for the sausage but its not happening. Being a new divers you can perhaps imagine our confusion.
    Next thing i know he gets close to me, looks at my gauge and proceeds to hand me his spare and we go along for a while sharing air.
    I have to admit that this confused the hell out of me. At first i thought wth is he doing, is he gonna let me run our of air and i'll be resting here with the tortugas?
    Eventually he handed me back my own regulator, at this point 500psi were left.
    During the time i was breathing from his spare i tried to make sense of what was going on and all i could think of was that he wanted me to save the air i had left for the safety stop and to safely get back up...but that didn't quite make sense since my husband was on 700psi at the same time as me, so at this point scary thoughts were going through my head, meanwhile we are being "attacked" by some big fish that was very attracted to the yellow of the spare and insisted on nibbling on it, he hung around us all the way to the surface. At one point when i turned around I had this fish with a big open mouth right in my face lol.
    So back on the boat the DM said that actually the reason we shared air was because he still had 2000psi and to prolong the dive a bit longer.

    So here comes the question...is this OK, is it common practice?
     
    Last edited by a moderator: May 23, 2012
  2. Teamcasa

    Teamcasa Sr. Moderator Staff Member ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: Near Pasadena, CA
    12,122
    432
    0
    It happens, but (in a non-emergency situation) it's usually when a buddy pair has a large disparity in air consumption rates. I've been known to (after asking) grab my wife's octo and suck down a little of her gas to extend our mutual bottom time. This happens more on vacation dives where I can't rent a larger tank.

    The practice should be discussed as part of your dive plan so there is no confusion.
     
  3. TSandM

    TSandM Missed and loved by many.

    # of Dives:
    Location: Woodinville, WA
    36,350
    13,508
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    It's not the first time I have heard of this being done, but I don't like the way it was done very much.

    My husband and I often share gas for a little while during a dive, if we are having to use the same size tank. But we do it very early in the dive, when both of us have a lot of gas. I have, on occasion, shared gas with someone who ran somewhat low, as you did, if the place we were in was not ideal for surfacing. For example, there is a nice dive here on a wreck that's right outside the mouth of a marina; although one COULD surface directly from the wreck, it's not a great option except in an emergency, so when someone ran low on gas, I just shared with him so we could swim closer to our boat before we came up.

    But in general, I don't think it's a good practice to allow someone to run low on gas and then extend their dive time -- people who are low on gas should be getting shallower, especially if they have run low quickly, because if they get separated from that donated gas source, they're going to run through what they have left pretty quickly, too.
     
    SubMariner likes this.
  4. ktomlinson

    ktomlinson Instructor, Scuba

    # of Dives: 200 - 499
    Location: Statenville, GA
    1,035
    162
    63
    I've buddy breathed with my wife to extend our mutual bottom times too...the only time a DM offered me extra gas was earlier this month in Australia, I signaled that I was at the turn pressure and let me share with him for a while instead of me going back to the boat. I appreciated it since I got to see a wobbegong shark and since I could have always made the choice to ascend on my own if I felt the need.
     
  5. OzGriffo

    OzGriffo DIR Practitioner

    # of Dives: 100 - 199
    Location: Melbourne, Australia
    1,045
    356
    83
    I've done it in OW in similar circumstances. I'd hit turn pressured, the DM still had heaps left. We got another 10 minutes or so, then I went back to my supply for the ascent and stop.
    I'm not smart enough to comment on the merits of it, but I would certainly only ever have done it in OW where a free ascent was possible if all else failed, and certainly never ever if a diver went below the minimum gas, or turn pressure.
     
  6. awap

    awap Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Central TX
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    3,698
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    My buddy/wife and I do it somewhat regularly when one of us has a heavy breathing dive or a short fill. Usually planned in advance to start the air share when the lowest tank is at 1000 psi. That usually means we have already started a slow ascent and can extend the dive 5 or 10 minutes with no problem and plenty of gas in each diver's tank. Did it with my newly certificated granddaughter a couple months ago on a long, shallow crlear spring dive. She had no problem as we had practiced just such a thing in the pool on a few occasions. If you expect divers to be able to do such an air share in an emergency, it should not be a problem to do it in a non-emergency situation. Extending the dive is just a great side benefit.

    I know my wife and granddaughter can deal with a share air situation with absolutely no problem. I just don't see the down side as long as the dive conditions are not a challenge.
     
  7. t4e

    t4e Regular of the Pub

    # of Dives: 100 - 199
    Location: Burlington Ontario
    727
    231
    43
    thank you for the replies, it makes me feel better, i only wish i knew ahead of time that he would do that, but in any case the fact that my husband was on the same air level as me was what worried me the most, i guess the other diver would have shared their air with him provided they had enough left
    we have another dive tomorrow and i'll make sure we cover this aspect of the dive plan
     
  8. TSandM

    TSandM Missed and loved by many.

    # of Dives:
    Location: Woodinville, WA
    36,350
    13,508
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    One word -- if you ever plan to do this, discuss it with the dive guide in advance! We had a guide in Indonesia who had a conniption fit in the water when he saw us sharing a reg, even though we showed him our gauges that proved that we were absolutely fine.
     
    chrpai likes this.
  9. awap

    awap Solo Diver

    # of Dives: 1,000 - 2,499
    Location: Central TX
    14,852
    3,698
    113
    I agree it is better to advise all involved what may happen but if an OK sign does now calm a "conniption fit", the dive guide has the problem including the lost tip.
     
  10. PeterNBiddle

    PeterNBiddle Manta Ray

    # of Dives: 100 - 199
    Location: Seattle, WA USA
    832
    384
    63
    We did this pretty routinely in Coz in April.

    We always discussed it up top beforehand and the DM told us that we'd only do it if we were comfortable with it.

    Our DMs don't split up groups with multiple ascents so sharing air meant that we routinely got 60+ minutes and the primary we used was a 6 footer so it wasn't very cramped.

    As an occasional air hog I really liked it.
     
    eternaljonah, GOCACHN and motorref like this.

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