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Why extra air when solo?

Discussion in 'Solo Divers' started by pauldw, Jul 11, 2019.

  1. John C. Ratliff

    John C. Ratliff Instructor, Scuba

    # of Dives: I'm a Fish!
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    The highlighted text is true only for single hose regulators, but not for double hose regulators. For decades double hose regulators were the standard for diving in the Antarctic. But they were discontinued by the manufacturers, fell into disrepair, started leaking sea water into the case, and then freezing up, so were discontinued. But double hose regulators have a distinct advantage over single hose regulators, in that both the first and second stages are isolated from the water. The double hose regulator therefore will not freeze up under normal use.

    Concerning single hose Regulators and freeze-up, here's an interesting study:
    I will have more to say later.

    SeaRat
     
    BlueTrin likes this.
  2. Steve_C

    Steve_C Divemaster

    # of Dives: 500 - 999
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    Had a mouthpiece come off. Yes, I could still breath off that. Simpler to just use the other second stage and finish the dive.

    The fact that I am diving in a solo configuration does not mean I am actually diving solo. I dive in a solo configuration with most instabuddies. Have had to do a couple of temporary air shares while we sorted out their issues or extended their dives. Pony is a 19 and prefer to leave it alone and full in those cases where it is essential.
     
    Satrekker likes this.
  3. John C. Ratliff

    John C. Ratliff Instructor, Scuba

    # of Dives: I'm a Fish!
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    In addition to being a diver for a very long time, trained by both the U.S. Navy and the USAF, and a diving instructor (NAUI #2710), I have worked in the occupational safety and health, and industrial hygiene, fields for over 30 years before retiring. In the latter career fields, we have what is called a Risk Assessment Matrix, and a Heirarchy of Controls, from a ANZI Z10 Standard for Occupational Safety and Health Management Systems.

    We'll talk about the Risk Assessment Matrix first (see below). In the occupational safety and health field, if we have a situation for which the severity is potentially catastrophic, which could lead to death or permanent disability, and the likelihood of occurrence was "Frequent," meaning it was likely to occur repeatedly, it was rated in the "red zone" as "High," and the "Operation was not permissible."

    What has been described in the discussion of diving in extremely cold water with a single hose regulator likely to freeze up fits into this "Red Zone" category, and the operation should not be allowed to occur.

    In the "Heirarchy of Controls," you will notice that the controls most effective are "Elimination," "Substitution," and "Engineering Controls." The least effective are PPE (Personal Protective Equipment) and "Administrative Controls."

    There are differences between different single hose regulators, and some are much more prone to freeze-up than others. This is clearly shown in the International Polar Diving Conference publication. On page 35 of this document there is an article titled:

    SCUBA REGULATORS FOR USE IN COLD WATER: THE U.S. NAVY PERSPECTIVE
    John R. Clarke
    Navy Experimental Diving Unit 321 Bullfinch Road Panama City, FLORIDA 32407-7015 U.S.A.

    This article should be consulted about regulators, and their ability to be used in frigid conditions.

    I discussed the possibility of using a current double hose regulator instead of a single hose regulator. This is an "engineering control" which is much higher up on the hierarchy of controls. The double hose regulator has both the first stage and second stage sitting in air, and not subjected to the diver's breath (which is very humid). The Argonaut Kraken regulator is the only current double hose regulator being manufactured. I have talked with Kraken divers who've used it under ice in the Mid-West/Canada, and they have not experienced freeze-up with this regulator.

    I have dived for over 55 years, and had exactly one freeze-up of my single hose regulator. That occurred in a lake on the Oregon coast with a water temperature of 37 degrees in February (winter here). The regulator was a AMF Voit MR-12II, with the Venturi located external to the regulator in a metal tube going to the mouthpiece. To fix that, I did not get a backup octopus, but rather bought a Sherwood Maximus Blizzard regulator, which has heat retention vanes in the regulator. The above report stated this from the U.S. Navy:
    This also is an engineering control (using tested regulators for cold water diving).

    Redundant air is great, but redundancy with a compromised regulator design in cold water may not be the answer.

    SeaRat
     

    Attached Files:

    Bob DBF likes this.
  4. martincohn

    martincohn Solo Diver

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    Incase you run into some putz that wasn't looking at his gages and is OOO.

    "Sure here ya go buddy (not my dive buddy) take my long hose and I'll save your life. You owe me a beer!"
     
  5. Storker

    Storker Divemaster

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    If I were an occasional solo diver, I'd resent removing my ordinary 2nd and plugging the 1st stage port every time I was solo diving.

    Much easier to keep my buddy config and just add the pony when I was solo diving. Plus, of course, keeping my gear consistent.
     
    Steve_C, Bob DBF and pauldw like this.
  6. doctormike

    doctormike ScubaBoard Supporter Staff Member ScubaBoard Supporter

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    Why not just give him your pony and ascend? Better to stay away from people like that!
     
    BlueTrin likes this.
  7. martincohn

    martincohn Solo Diver

    # of Dives: I just don't log dives
    Location: USA
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    Redundant gas doesn't always = pony. I'm one of those sidemount weirdos.
     
  8. doctormike

    doctormike ScubaBoard Supporter Staff Member ScubaBoard Supporter

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    No, but the OPs question was about a pony bottle.
     
  9. KenGordon

    KenGordon Rebreather Pilot

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    I have had/seen a few. Some caused by deliberately dumping gas for a weight check in fresh water, and one this year which seemed to be caused by overbreathing in deepish cold fresh water. Our club regs are supposedly cold water compatible but I will no longer let people use them in particularly cold water. We are generally not diving with very low air temperature, but shallow inland sites can get really cold, and the deeper ones never warm up at depth, so the stress is different.

    The bloke I referred to that died got his freeflow doing a DSMB deployment at 20m odd in a site that goes to about 35m.
     

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