Two straps, one tank

Discussion in 'Buoyancy Compensators (BC's) and Weight Systems' started by Blue982, Oct 17, 2009.

  1. Blue982

    Blue982 Nassau Grouper

    # of Dives: 50 - 99
    Location: Seattle, WA
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    Hey everyone,

    So I've seen some people with two straps attaching their tank to their BC. I assume it's for trim (less tank movement relative to the BC.) Are there any other benefits? Are there certain BCs you would want to (or not want to) add a second strap to?

    I've tried to search for previous threads but I'm not really sure what this would be called and so I was unsuccessful.

    Cheers and thanks in advance
     
  2. *dave*

    *dave* Scuba Instructor

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    Redundancy and stabilty are the primary advantages.

    Welcome to SB.
     
  3. Blue982

    Blue982 Nassau Grouper

    # of Dives: 50 - 99
    Location: Seattle, WA
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    Thanks! I'm diving a Sherwood Axis, can a second strap be fitted to it?
     
  4. deepseafalcon

    deepseafalcon Nassau Grouper

    # of Dives: 200 - 499
    Location: China (temporarily)
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    I often observed people loosing their tanks (well, not really loosing due to the hoses, but getting in serious distress). I would say that's the most frequent serious distress situation I have witnessed in recreational diving. Partially because of hurry on deck of large dive boats, partially because of inexperience or ignorance of the divers themselfes.

    In virtually all cases, they had BCD with only one cam band. So in my opinion, two cam bands is one of the most useful redundancies. I would recommend it for all BCD that can accept a second band. Just look closely if the integrated backplate has a second pair of slots allowing to thread one.

    I even added one to the Mares Vector Origin of my wife. Which, btw, is one of the most simple and inexpensive, but nevertheless functional and durable BCDs out there. She's happy using it for 10 years now, doesn't want a BP/W ;)

    Stability is another reason: If you look closely, you can occasionally see divers with their tank slightly diagonal across their back. Maybe it's to look cool, but I'm afraid rather not ;)
     
  5. BuoyantC

    BuoyantC Scuba Instructor

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    Some of it depends on the BC. Many single strap models use a "cradle" usually lined with a gripping material. A single strap can then hold the tank quite securely. If you try to add a second strap, even if there is a space, the locations may not be too useful. For example it could be so high as to slip off the curved top portion of the tank.

    Two strap models often lack the cradle and need two straps for stability. The best way to prevent tank slippage is to use care in clamping the tank. Even two straps will not make up for sloppy pre-dive preparation.
     
  6. mpgunner

    mpgunner Nassau Grouper

    # of Dives: 50 - 99
    Location: Seattle, WA
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    I love the two straps on my Ranger. Never have to worry about slippage.
     
  7. readysalted

    readysalted Angel Fish

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    I have a Tusa BCD with only one strap,which i feel very secure with, and dare i say if the equipment is put together correctly then there should be no problems?, i have been diving for 10 years with one strap bcd's of one form or another and not lost a tank?.
    But when all is said and done it all come's down to what you are most happy with.
     
  8. vel525

    vel525 Barracuda

    # of Dives: 200 - 499
    Location: Cambridge, MA
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    I think 2 straps are nice for the previously mentioned reasons, but not necessary. I think it's more important that if you have one strap it's a high quality one. I've seen lots of tanks slide down during the dive (especially people who tend to dive vertically) and have seen plastic ones break. I really like the SP style cam bands. Once locked down I have never seen one come loose during the dive (however, I have personally not locked down the strap and jumped in and that did not work so well :D)
     
  9. mksmith713

    mksmith713 Manta Ray

    # of Dives: I just don't log dives
    Location: Jupiter,Fl
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    I've seen too many one strappers have their regs pulled from their mouths by tanks falling out of the strap.
    Two is wayyyyy better.
     
  10. Walter

    Walter Scuba Instructor

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    Most tank straps are poorly designed and don't hold well. You really need two straps to ensure the tank doesn't drop out. If you have Scubapro straps, you don't need a second, they hold really weel.
     
  11. D_B

    D_B Biilápache, Dii Shodah? ScubaBoard Sponsor

    # of Dives: 50 - 99
    Location: San Diego, Ca.
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    Walter posted what I was thinking.
    It depends on the strap, I have my SP one set, and It stays put, never slipped .. dont even wet it before using it any more (still check it though)
     
  12. spectrum

    spectrum Dive Bum Wannabe ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: The Atlantic Northeast (Maine)
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    From a design perspective 2 straps will keep the cylindrical positioned much better. Support features can serve to cradle and align the cylinder but binding it down in 2 spots is hard to beat.

    The basic standard cam band works well enough but a new one that is stiff or a diver lacking good technique will have a hard time getting predictable results. In that case they double the chances of getting one of them good and tight.

    There are a number of other buckles out there including the mentioned Scubapro product that take the technique out of it all. With those you will get the single strap predictably secure and not need to worry and a breakaway cylinder.

    Pete
     
  13. Davidstealey3

    Davidstealey3 Divemaster

    # of Dives: 200 - 499
    Location: Maryland
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    of all the bc's i have seen, the ones with a single strap all have a hard plastic bp type device in them.

    the reason i think a lot of the people loose the tanks is because of improper instruction at the time of purchase. when we do OW we teach the students to wet the bc strap before attaching to the tank. the belt will loosen up after it is wet allowing the tank to " slip " out. wetting the strap and checking for tightness but picking up two inches and shaking the tank and bc will let you see if it is loose. also the strap will eventualy streach over time and will need to be tightened up.

    that being said i dont think there is much of any advantage of a single over a double strap bc. it is just what you like to use.
     

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