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Redundant / Emergency Buoyancy. Lift Bag vs SMB

Discussion in 'Lift Bags, SMBs and Reels' started by CaveSloth, Jun 5, 2019.

  1. CaveSloth

    CaveSloth Barracuda

    # of Dives: 50 - 99
    Location: The Deep South
    390
    83
    28
    Calculations say that I may need 25 lbs of redundant buoyancy in case of BCD failure. I already have a redundant bladder, but want a third buoyancy source. I dive in fresh water spring caverns in Florida mainly. I am a DiveRite fanboy. Should I choose the DiveRite SMB or Lift Bag? SMB has 30 lbs lift. Lift Bag has 75 lbs of lift. Both look like they have dump valves from the pictures. Which would be easier to deploy and use in an overhead environment? Comments on technique would also be appreciated. Thanks!

    Dive Rite { 5 ft | 1.5 m } Surface Marking Tube w/Built-in Sleeve

    Dive Rite Lift Bag {75 lb | 34 kg} w/Built-In Sleeve
     
  2. chrisch

    chrisch Solo Diver

    1,062
    340
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    I would think the tube is easiest to use in a confined space - you could inflate it partially and then place it under your chest either end under the arms like a swimming float.

    Seems a rather odd thing in an overhead environment to me. A drysuit would be a better choice IMHO.
     
  3. kelemvor

    kelemvor Big Fleshy Monster ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Largo, FL USA
    5,935
    3,140
    113
    Personally, I would choose a dsmb that did not have an open bottom. Seems like the open bottom would make it a lot more difficult to manage when using it not-as-intended.
     
  4. rongoodman

    rongoodman ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Albany, NY
    5,020
    1,686
    113
    Unless the SMB is full, the dump valve will be nowhere near where the air is, so not of much use. Why do you think you need three sources of buoyancy, and if so, why not just dive dry?
     
    Lorenzoid likes this.
  5. johndiver999

    johndiver999 Manta Ray

    # of Dives: 500 - 999
    Location: Gainesville FL
    919
    827
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    Overhead environment and both means of buoyancy fail- then crawl out of the cavern?
     
  6. CaveSloth

    CaveSloth Barracuda

    # of Dives: 50 - 99
    Location: The Deep South
    390
    83
    28
    Yes, absolutely, one of the few safety advantages of cavern diving.
     

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