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SMB / Safety sausage deployment at depth

Discussion in 'Basic Scuba Discussions' started by geoff w, Mar 1, 2011.

  1. =C=

    =C= Instructor, Scuba

    # of Dives: 5,000 - ∞
    Location: The third planet (a smaller one but a nice blue hu
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    So this is how to do it:



    The thing is the spool needs to be ready, free, and clear. Stop if you have any extra line hanging.

    Also, remember physics.. its doesn't take much air at depth to have a full bag at the surface. Finally, while there are a couple of techniques you can see on youtube the technique I like is to inflate orally as there little added buoyancy to manage. The air goes out of my lungs and into the bag...

    O and ignoring the jerks.. I see you are PADI and would suggest a SAR specialty course from you instructor, its fun and will get you working on some skills before your trip.
     
    j yaeger likes this.
  2. TSandM

    TSandM Missed and loved by many. Rest in Peace

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    SMB deployment is definitely a skill and it takes practice. Small bags (the 3'/1m ones) can easily be deployed without much of a buoyancy issue . . . but although I say that, it took me quite a while to master it. I learned that I could tip a bit head-down and fin downward gently while inflating the bag, and then let go of it, and I didn't have to do any fancy buoyancy adjustments. For larger bags, the problem is bigger, and they are best shot at deeper depths, where you can put less air in them and still have them full on the surface.

    The biggest risk of bag shooting is getting entanged in the line or the clips, and getting dragged to the surface. You can minimize that risk by making sure you are horizontal when you go to shoot the bag, and keeping your hands well out in front of you during the process. (Being vertical or near-vertical exposes a lot more of the front of you to the risk of entanglement.)

    I highly recommend some practice in a shallow, controlled environment, like a pool or a shallow shore dive. (I practiced mine in 10' of water off Old Airport Beach in Maui!)
     
  3. dbulmer

    dbulmer DIR Practitioner

    # of Dives: 500 - 999
    Location: UK,Windsor
    1,416
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    I disagree with you slightly.

    I agree with your point about getting good input and supervision - it's essential.

    Where I nitpick is your assertion about the DCI stats. I think you can be very well trained in blob deployment and still *ock it up. For me at least putting up a blob is about the most dangerous portion of the dive.

    To reduce the risk with blobs you need the input and supervision, and then you need to get into the habit of putting up the blob as quickly as possible. I find that when I am slow in putting up a blob that is, when more often than not, it goes wrong.

    It also really helps if you have a buddy watching you carefully - a second brain can help if it goes wrong :)
     
  4. =C=

    =C= Instructor, Scuba

    # of Dives: 5,000 - ∞
    Location: The third planet (a smaller one but a nice blue hu
    541
    33
    28
    My 2c:

    Quicker ≠ Better

    Take time, watch depth, and when your ready launch the bag.

    Im not too sure about the DCI assertion either... Have a source?

    What I see with students is that they drop their heads and start to drop into the deep blue. They focus on the bag and forget about diving when the reality is you have tons of time for the SMB...

    When it comes to buddies they tend to both try the SMB at the same time...
     
  5. Splitlip

    Splitlip Great White

    # of Dives: 500 - 999
    Location: Jupiter
    3,913
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    Another Tip if you are using an open bag. Transfer any air in your BCD to the bag using the inflator. Your Buoyancy and postion in the water column stay the same. When I had an open circuit bag, that's what I did. Stands the tube up nicely. And depending on how you are weighted, that might be all that is needed to get a full marker at the surface. But I still went negative and finned when I put the second stage in.

     
  6. Splitlip

    Splitlip Great White

    # of Dives: 500 - 999
    Location: Jupiter
    3,913
    467
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    Thank you Andy. I have gotten a ration of $hit for going negative and finning when I shoot. But somebody shoots virtually every dive I am on. And we have big ones. Getting a 40 -55 lb marker full from rec depths usually requires it.
     
  7. paddler3d

    paddler3d Divemaster Candidate

    # of Dives: 200 - 499
    Location: Baltimore, MD
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    If you get formal training or not on how to deploy a SMB from depth, or not, you're choice. It is a skill that is well worth practicing. Start off shallow and practice. Deploy, recover, deploy, recover. You can do that for a bit in shallow water, say 10ft or less, without risk of really hurting yourself. Instructors do these little bounce dives all day.

    Then practice a bit deeper. Then add it on to the end of the Safety Stop. eventually add it at the beginning to the safety stop. Then practice shooting at deeper.

    It isn't a hard skill. It is a skill that if you do it wrong, you can get hurt.
     
  8. Splitlip

    Splitlip Great White

    # of Dives: 500 - 999
    Location: Jupiter
    3,913
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    From a friend who got tangled in the line of a big bag.

    "Scream! (keeps the airway open) and fin down if you can in order slow the exponentially increasing rate of ascent."
     
  9. EmptyTank

    EmptyTank Regular of the Pub

    # of Dives: 100 - 199
    Location: not close enough to the ocean
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    I have never needed to shoot a bag so to speak. Why do people have so much trouble? It looks like a walking and chewing gum at the same time skill. I am not meaning to be glib so save the flames for someone else.
     
  10. Deefstes

    Deefstes Loggerhead Turtle

    # of Dives: 100 - 199
    Location: Johannesburg, South Africa (not close enough to th
    1,396
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    I daresay, addressing the first sentence would answer the second. Go shoot a bag and you will notice that it is not as straight forward as it may seem.

    I *think* the reasons it is so tricky (and I'm not saying it is dog difficult, just tricky) are:

    - You're required to take your mind off diving and concentrate on something else. For experienced divers this part should be a cinch but this is exactly where many divers start forgetting about their buoyancy, proximity of the reef etc.

    - You're involved in an exercise that involves exchange of air between different containers (cylinder, BC, SMB) fairly rapidly, which will affect your buoyancy and you need to be ready to deal with that.

    - Unlike mask clearing which you can do as many times as you like until you get it right, shooting an SMB is an exercise that you have only one shot at. Once you've inflated the SMB and let go of it, it's gone. You can't reel it back in and try again. If you didn't add enough air to it, it will be limp on the surface until your dive is over.

    - The risks involved in getting it wrong are significantly bigger than many other skills. If you get mask clearing wrong, you can't see for a while. If you get buddy breathing wrong, you just switch back to your own primary or octo. If you get shooting an SMB wrong, you lose the SMB or you get dragged to the surface.
     

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