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Setting up hoses on a doubles set.

Discussion in 'Technical Diving' started by TheCanuck, Jul 9, 2011.

  1. ajduplessis

    ajduplessis Solo Diver

    # of Dives: I'm a Fish!
    Location: dry land :-(
    3,256
    836
    First off, I am not cave certified.

    I don’t agree with the argument having the primary on the left post so the diver will be the “first” to notice a possible roll-off. If you are really diving in an environment where this amount of roll-off is possible, you should not be diving manifolded doubles, but rather independent doubles (side-mount). Is diving not about using the correct gear for the type of dive you want to execute? If you are entering restricted areas I would want a flat as possible profile.

    My 2 cents.
     
  2. Ste Wart

    Ste Wart Master Instructor

    # of Dives:
    Location: England
    1,613
    573
    Good point. But that assumes that you would want to learn sidemount. Which is a completely different configuration in itself. And you would have to go back to swapping regs when you reach a certain pressure, rather than have than have the continuity of manifolded twins. You gain certain advantages with sidemount, but lose others.

    Roll off is a 'what if' issue. But if that what if occurs, I know I'd like to be the first person to know about it.

    Swings and roundabouts.
     
  3. ajduplessis

    ajduplessis Solo Diver

    # of Dives: I'm a Fish!
    Location: dry land :-(
    3,256
    836
    If I ever require the need to enter restrictive areas in a cave I would definitely get trained in side-mount, as it seems to me to be the best setup for this type dive. I get trained because I want to dive in a certain environment. Breathing of different regs (side-mount) during a dive is not necessary a bad thing by the way.

    IANTD trained me to test my backup before I put it in my mouth, thus I will be the first to know if the left post is roll-off, no surprises here. I also check my pressure periodically.

    But this is only my opinion and nothing more. I appreciate your inputs thou.

    Regards
    ajduplessis
     
  4. Ste Wart

    Ste Wart Master Instructor

    # of Dives:
    Location: England
    1,613
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    We're approaching it from 2 different angles. I'm not keen to do cave, if ever. So sidemount for me is fairly moot, add to that I'm edging towards rebreather, then my own personal view is that sidemount is a step sideways for me, solely because of how I wish to dive in the future. But I can see where you're coming from with the flat profile thinking.

    I did my courses with IANTD also; and my instructor dives left. But I don't teach left. I let the student choose whatever they like. Basically this is me, how do you wish to configure. Now it's a part of my diving I wouldn't want to change it. It makes total sense to me. What I like about IANTD is the flexibility with them. They have the maturity to say for example, it's no problem breathing of the short hose from the get-go. The equipment configuration section in the encyclopedia is also excellent, especially with Kevin Gurr saying how he likes suicide clips on his stage bottles, its refreshing to have people say this is how I dive, yes I know some people don't like this, but hey it works.
     
  5. elan

    elan DIR Practitioner

    # of Dives: 200 - 499
    Location: Toronto, Ontario, Canada
    3,316
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    wart what is the problem with checking the knob to verify if the valve is open after the impact ? So called flow check how GUE folks call it.
     
  6. TheCanuck

    TheCanuck Registered

    62
    6
    What would be the tec perspective why this is bad?

    I can see your point about doning/doffing the gear.

    About confusion with the long hose, doesn't it already flow where the long hose loops? The long hose routes around your neck, so if it meets the back up reg's hose behind your neck or to the left of your neck, what's the difference? I'm probably not seeing something. Not trying to criticize your post, just genuinely trying to understand
     
  7. TheCanuck

    TheCanuck Registered

    62
    6
    By the way, the class kicked my ass. Damned doubles! At first my harness was too slack, so I kept turtle-ing. After fighting with my right for 15 minutes, we surfaced, tightened my shoulder straps and tried a second time. Once under, I was still struggling, this time because I kept going face down. After 10 minutes of this, we surfaced once again and raised the backplate and tried again. Within 10 minutes I was in trim and buoyancy was OK while swimming. I'm still struggling when trying to hover.

    We practiced OOG diver drills, valve drills, reel deployment, lift bag deployment, mask clearing, mask removal and clearing, free flowing power inflator drills and spooling line. Kept looking at the floor/my rig during drills at first but caught one pretty quick and kept eye contact with my instructor.

    Clearly I need more practice with doubles before I go further with this. We agreed I should get another 6 to 8 dives of practicing clipping/unclipping gear and just practicing the drills while hovering before we met again to complete the class.

    Overall I'm glad I did this. Taught me new skills and had to learn to dive in a whole new way.

    The dry suit posed no issues except for the fact the bugger is leaking. Gotta bring it in to get checked out. First time diving with it, although I did buy it used.
     
  8. Jaydubya

    Jaydubya PADI Pro

    # of Dives: 1,000 - 2,499
    Location: NC
    310
    67
    Nobody goes through a restriction that is too small on purpose but it can happen.

    I had a roll-off in a zero visibility air share simulation. The passage was completely passable in backmount, if you could see. I bet my buddy was glad I had my long hose on the right post and I was glad I knew how to turn my valve back on.

    Right post roll offs are more rare, but they can happen. I once had a right post roll off while descending to a wreck - the anchor line rolled the valve knob.
     
  9. TheCanuck

    TheCanuck Registered

    62
    6
    I just figured what you guys meant by roll off. Carry on.
     
  10. Ste Wart

    Ste Wart Master Instructor

    # of Dives:
    Location: England
    1,613
    573
    Having the primary on my left negates he need to check. I'm informed once the flow is interrupted. Then, and only then, do I need to reach up. As I've mentioned this would be the scenario for 99.9% of all dives, so the only time I would need to do a flow check would be when I've donated the primary to exit.
    Proper gas planning and monitoring air supply is talked about a lot on the board. So the chances of my tech buddy running low on air in any situation should be next to zero. Add into this the majority of my diving is deep reef and wreck. Then the chances of a roll-off drop further still.
     

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