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Which CCR?

Discussion in 'Rebreather Diving' started by ATJ, Jan 5, 2015.

  1. ATJ

    ATJ Barracuda

    # of Dives: 1,000 - 2,499
    Location: Sydney, NSW, Australia
    268
    139
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    I am considering getting a CCR mainly for diving around Sydney, Australia but would also use it further afield where appropriate.

    There is a particular dive site in southern Sydney (called The Leap) which I dive very frequently and I think a CCR would be very useful. The site is usually a shore dive and is essentially a drift dive with the entry and exit points being are around 500 metres apart. You jump in at the entry point and swim to the sand line which is just over 20 metres and drift/swim along the sand line which gradually gets shallower. The site can be easily dived on air with a regular 12.2L tank but you don't get to spend much time looking for cool critters. If you dive on air you can't spend much time at the start of the dive because you hit your NDL quite quickly. I usually dive the site with a 15L tank with Nitrox which gives me more bottom time.

    The site has a lot of really cool critters with the Sydney pygmy pipehorses being the way coolest. The pygmy pipehorse are tiny (maximum length 55mm) and can be very difficult to find. You could spend 30 minutes looking at just one rock for them but finding them is a thrill. I am finding that even with the 15L tank I'm not getting enough time to both look for pygmy pipehorses but also look for the other interesting critters such as seahorses and weedy seadragons.

    I think a CCR would be the logical choice to get more bottom time. I should mention that both the entry and exit points are at the bottom of cliffs and are accessed by steep steps. I can cope fine with the 15L even in my dry suit but anything larger (such as an 18L or twins) would be unmanageable. This is another area where a CCR would excel.

    I completed training on a Poseidon MkVI in 2012 (TDI MkVI Discovery Air Diluent Diver) but never went on to buy or hire one (the plan was to use one on a subsequent dive trip but circumstances changed). I quite liked the MkVI and know it would do the job although I'd at least need a refresher course.

    I am wondering what other options I might have.
     
  2. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

    # of Dives: I'm a Fish!
    Location: Greenville, South Carolina, United States
    17,082
    8,881
    113
    bollocks, my post just got deleted.

    Quick version
    MkVI training translates over to the 7even. Buy a used VI if you want to stay with that unit, it's about $3500-$4000USD. A few for sale on CCR Explorers and Rebreather world. Take a day with your instructor as a quick refresher and you'll be good to go.

    Fortunately/unfortunately, what you are describing for wants/needs and dive profiles is actually a SCR. They're cheaper, easier to setup, easier to maintain etc, since they are basically just a way to extend a nitrox tank for a few hours. Grab a nitrox tank with the mix you want, go dive for a few hours without bubbles, and good to go. Downfall is it doesn't extend your NDL's by giving you a constant PPO2 which is an advantage of an ECCR. You should also take your AN/DP course since the cheap way to go about this is just to carry an al40 with O2 and do decompression for the last 10 minutes or whatever.
     
    the_dragon_no1 and muddiver like this.
  3. ATJ

    ATJ Barracuda

    # of Dives: 1,000 - 2,499
    Location: Sydney, NSW, Australia
    268
    139
    43
    Thanks. Deco is not generally a problem for this site. When diving with 32% I think the closest I have got to my NDL is 40 minutes and as you generally get shallower as you progress at the site you you get more no-deco time back as you go. The main thing is extending the time the mix lasts.

    Carrying an extra tank might help but I would also have to carry it back up those steep steps.
     
  4. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

    # of Dives: I'm a Fish!
    Location: Greenville, South Carolina, United States
    17,082
    8,881
    113
    al30's are pretty light if you go the deco route, but if you aren't hitting ndls' on single tanks, then it is what it is. On a CCR you obviously can deco on the breather if there's stuff to look at at 20ft. I would seriously consider going to a SCR or used MKVI though if you are strapped for weight.
     
  5. hroark2112

    hroark2112 Tech Instructor

    # of Dives: 0 - 24
    Location: Raleigh, NC
    1,312
    1,230
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    Every rebreather diver is going to say their unit is the best :D

    I dive the Kiss Spirit LTE. It's light, easy to dive and very easy to control your buoyancy even in very shallow water. It is an mCCR, so you'd have to learn a new unit.
     
    muddiver likes this.
  6. Dsix36

    Dsix36 Solo Diver

    1,505
    1,069
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    Although I think my brand of rebreather is pretty darned awesome, in this case I tend to agree with the previous poster that a SCR would be the best best due to weight restraints and the actual dives being done.
     
  7. muzikbiz22

    muzikbiz22 Manta Ray

    # of Dives: I just don't log dives
    Location: Southern California
    1,144
    389
    83
    I'm going to agree as well, and take it a step further. Hollis Explorer.
     
  8. muddiver

    muddiver Divemaster

    # of Dives: 500 - 999
    Location: West Coast USA
    2,630
    104
    63
    Buy a kiss. They use loose absorbent that is the lests expansive, the lightest of the units available, a true Close Circuit Rebreather so you can adjust the oxygen partial pressure to reduce nitrogen loading and shorten decompression time.
     
    hroark2112 likes this.
  9. ScoobaChef

    ScoobaChef DIR Practitioner

    # of Dives: 1,000 - 2,499
    Location: Sydney
    185
    54
    28
    Go have a chat with Bazza at Southern Cross Divers in Mosman. He can teach most units on the market but lately has been focusing on the JJ. He's usually got a number of used units for sale in the shop if you wanna check some out before you buy.


    Now that I think of it, pretty sure he has a mkVI on hand.
     
    Last edited: Jan 7, 2015
  10. Mr.X

    Mr.X ScubaBoard Supporter ScubaBoard Supporter

    2,449
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    Is that Aussie rebreather website still around. It so - there would be nearly two decades worth of info. on there? If not, the oft-contentious, chest pounding hero site called Rebreather world.
     

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