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Dual tanks configuration question

Discussion in 'General Scuba Equipment Discussions' started by cathellm, Jun 19, 2011.

  1. mathauck0814

    mathauck0814 Instructor, Scuba

    Mine quickly remembered the ~$1200 shoe collection and feigned encouragement :) Too funny, though.
  2. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

    # of Dives: I'm a Fish!
    Location: Greenville, South Carolina, United States
    mine just said I had to buy her one too...

    I agree on the balanced rig. According to that I can only dive AL80 doubles with my wetsuit and can't dive hardly any steel singles with a wetsuit... I sink. I dive dry most of the time, but even in my transpac with a 5mm double 72's will sink me like a sack or bricks. I compromise balanced rig for the irritation involved in diving with AL80's...
  3. TSandM

    TSandM Missed and loved by many. Rest in Peace ScubaBoard Supporter

    Sorry, I can't leave this one alone. Where you are, saxplayer, this may be true, but across the DIR/GUE diving world, it is not. Most of the DIR divers here in the Seattle area are diving DSS gear, actually. And with a few exceptions, GUE classes are brand-agnostic.
  4. tbone1004

    tbone1004 Technical Instructor ScubaBoard Supporter

    # of Dives: I'm a Fish!
    Location: Greenville, South Carolina, United States
    NC. There was a huge Halcyon spike out here and the instructors here are brand agnostic but they push Halcyon gear hard. The DIR groups were out here a long time ago though when GUE started. I haven't seen an instructor out here without Halcyon gear though. I know it's not 100% true but the majority around here do. Sorry got yelled at by a DIR guy the other day and was a little put off.
  5. Colliam7

    Colliam7 Tech Instructor Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Kents Store, VA
    I am really curious where this 'HUGE . . . spike' in NC, particularly in the Raleigh area, might be. I would expand that to the Durham area as well. If you take the two largest / most active LDS operations (in terms of new certs, dive training, dive travel, dive clubs, etc.) in the Raleigh area, one is not even a Halcyon dealer. The other is, but I am pretty sure that nobody in that shop would be a DIR Nazi, even if we do sell quite a bit of Halcyon gear.
    As well you should be. Who in the Raleigh area is a DIR Nazi? Nothing against being one, I just don't see them in action that much.
  6. SelkieDVM

    SelkieDVM Instructor, Scuba

    # of Dives: 200 - 499
    There are GUE instructors in North Carolina?
  7. Dr Wu

    Dr Wu Regular of the Pub

    # of Dives: I just don't log dives
    Location: The State Department adds pages to my Passport abo
    Why do you want to do something you know absolutly nothing about?
  8. Colliam7

    Colliam7 Tech Instructor Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Kents Store, VA
    Yes, at least for backmount doubles. Even then, you could set up manifolded or independent doubles, in which case the manifold is not part of the rig. For SM, bands would also not be part of the rig, and a backplate may or may not be depending on how you decide to set up a SM rig.
    The tank material and size depends on 1) your personal perferences and 2) the type (e.g. a) depth / time; b) salt water/ freshwater environment; and c) exposure suit - wetsuit/drysuit) of diving you are doing with them. For backmount, I dive doubled AL80s, HP steel 100s, 120s, and 130s. And, I like all of them. I sidemount in AL80s, HP 100s, and LP112s, and like all of them as well. Most people diving doubles are diving DIN, although that is not universally true. I would suggest you think DIN tank valves (and regs) if you are moving to doubles, but others may disagree. At one time, 300 bar was considered de riguer, but now with Thermo Pro valves, 230 bar is quite common, and I don't see that as a decision factor.

    As several have noted, it would be helpful to know what your goals in setting up doubles might be - diving deeper, diving longer, doing decompression dives, dives in overhead environments, etc. That might allow people to provide more informed response. You could dive dual AL40s in a SM configuration and that would be a 'dual tank' rig, but with limited gas supply.
    For backmount, many people set up the right post (first stage) to have the primary (e.g. long hose) second stage, and the primary (BCD) LPI hoses, while the left post has the SPG hose, the alternate (bungeed necklace) second stage hose, and the secondary (e.g. drysuit) LPI hose. That is not univessal by any means.
  9. AfterDark

    AfterDark Contributor

    # of Dives: 1,000 - 2,499
    Location: Rhode Island, USA
    I'm an independent doubles diver. I like the fact it gives me two separate air delivery systems, two primary regulators and redundant hose(s) for my wing and/or dry suit.
    I use 2 72 LP steel or 2 90 LP steel tanks. My wing is a 94lbs lift, more than enough.
    I also carry a 25lbs lift bag for secondary buoyancy. On most open water dives with a buddy, I’ll breathe one tank down to1500-1000psi and end my dive when the second tank is down to 1500-1000psi. This gives me plenty air for a SS and enough air for an OOA incident. If a regulator fails I still have another system to safely end the dive and surface.
    I like the fact I can transport or use them as singles. The only real down side is if one regulator / tank goes bad the air in that side is not accessible. That situation can be avoided by a manifold set. Since I can’t get my hands that far down my back to turn valves on a manifold it makes no difference to me. So for me it’s all up and no downside.

    I’m now considering acquiring 2 small tanks 50-60cuft range to use instead of a single.
    I use mostly singles when shore diving. Toting 2 72’s from shore is more work then I like. Two 50’s might be just the setup for shore diving ID’s.
    Last edited: Jun 21, 2011
    cc.harley likes this.
  10. stairman

    stairman Contributor

    # of Dives: 500 - 999
    Location: florida
    Not sure why you want to dissect my post for, I have my opinions as you do as well. Yea I live in Florida and for doubles 85's and 95's are the norm. Maybe he needs to ask what all the guys are diving in his area. As far as a balanced rig thay may be fine for you and him so have fun with it. I rely on redundant lift in case of primary wing failure. As far as you not knowing what a hot or cave fill is Im not gonna tell you. Keep diving your balanced aluminum 80's and you wont need to ever know.

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