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Solo Without an Octo

Discussion in 'Solo Divers' started by certainmisuse, Oct 4, 2018.

  1. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    You'll need a LP regulator hose, and a fitting for the end that converts it to a LP inflator quick-release fitting, for those times you don't want to have the spare second stage mounted on your rig. Alternatively, have two hoses: one with LPI quick release, one a reg hose set up with the Y-adapter and your octo. Simple changeout of the hoses depending on your buddy or not.
    JamesBon92007 likes this.
  2. TooManyHobbies

    TooManyHobbies Divemaster Candidate

    # of Dives: 100 - 199
    Location: Maryland
    So correct. We should be talking about "weak points" not "failure points". I know nothing of solo diving, and I'm a newer diver, but this is true of any technical industry. Diving is a failure point in and of itself. You take one of the core functions of life (breathing) and restrict it to a very specific method. Driving and flying each have millions of failure points, yet we do them safely all the time. A brick has almost no failure points. The difference is a brick can't do anything useful for us.
    Excessive failure points should be limited in any engineering, but when you add functionality, you add the potential of failure. Weak points should be well known and avoided where possible.
    the_ocean, John C. Ratliff and A.S.H. like this.
  3. 2airishuman

    2airishuman ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Greater Minnesota
    I have found that my solo dives generally involve one of two configurations:

    1) Single tank, BP/W, primary hose under one arm, secondary on a neck bungee.
    2) Manifolded doubles, either 72s, 100s, or 120s, BP/W, primary on right post with long hose, secondary on left post with neck bungee.

    I find that I prefer a twinset over a singe plus pony, and I have enough twinsets that I just dive those.

    If I do use a pony, it is slung and has its regulator attached to it with elastic bands. I do not change my backgas regulator configuration.

    I have a couple of tank holders with no BC set up with single regulators with the idea of them being good for shallow water uses like boat maintenance, but other than some experimenting I find that I prefer my regular rig.
  4. Sevenrider860

    Sevenrider860 Instructor, Scuba

    # of Dives: 1,000 - 2,499
    Location: Newnan, GA
    Wondering if you just describe Left/Right from a different perspective...

    Traditionally the primary w/ long hose is described as being on the Right post with the bungeed second on the Left post. This assumes describing the posts as you are wearing the BM doubles - Right Hand / Right Post.
  5. 2airishuman

    2airishuman ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: Greater Minnesota
    I just had it wrong. I edited my post, thanks.
  6. A.S.H.

    A.S.H. Solo Diver

    # of Dives: 100 - 199
    Location: Deep East Texas
    You wrote, and explained it with examples better then I did, thank you for that.
    I'm not an expert by no means on solo diving, I'm still learning something new every day.

    Proper Training.
    Proper Equipment for the Dive being Preformed.
    Dive Planning, Gas Management.
    Preventive Maintenance.

    On every dive you do, solo or with a partner. It's all the same..
    TooManyHobbies likes this.
  7. John C. Ratliff

    John C. Ratliff Instructor, Scuba

    # of Dives: I'm a Fish!
    Location: Beaverton, Oregon
    As a retired safety professional, I can tell you where the term "failure point" comes from. In product safety, there is a technique called "Failure Modes and Effects Analysis," or FEMA. This technique looks at each failure point, and analyzes the effects of that failure "upstream" and "downstream" of that failure.

    As an example, from my personal experience when diving solo, I was about to dive my Dacor Pacer Aero regulator. It has an Enduro safe second attached, an SPG computer, and a LP line to my BCD. This Pacer Aero is a plastic second stage that I had used before and cleaned by removing the cover and diaphragm, washing it out again, and replacing the two parts. For this dive, I did a pre-dive check by both using the purge button and breathing off it before entering the water. But upon entering the Clackamas River, in a current and with water about ten feet deep, I took my first breath, and all I got was water. I tried a second breath, and again, only water came into my airway. Almost choking, I switched to my Enduro safe second, used the purge, and upon breathing got good, dry air. I then completed the dive of about forty-five minutes on the Enduro second stage.

    What happened? Well, when I put the cap back on, the diaphragm was not seated into the top grooves, and so it did not seal. It is a screw-on top box, and it was not possible to visually see, or tactically determine that the seal was bad. When I tested the regulator, the purge button obviously worked, and I had enough vacuum with my breathing to get a nice easy breath in air. But in water, no way!

    Using FMEA, there were no effects upstream of this defect. The valve worked perfectly. Downstream effects in the air were hard to determine; there were no leaks, and I could breath off the regulator. But in the water, any inhalation brought only water into the second stage, with the possibility of drowning if there was not a safe second or octopus regulator. I had the Enduro octopus, and so there was actually no effect of the dive.

    How could I have determined that there was a problem with this second stage? If I had done a negative pressure check by either putting my thumb over the first stage air inlet seal on the body, and breathing, there would have been air entering the second stage through the leak. I could then have corrected the problem by unscrewing the cover, reseating the diaphragm, and screwing the cover back on, then again checking that the seal was good.

    I dive many different configurations, using both single hose and double hose regulators. I dive a snorkel too, on my mask or helmet. If I have a double hose regulator I am not sure of, I have a set of twin 45s with a Sherwood twin-post manifold, and mount a second regulator off the extra post. But many times I will dive a Mistral or other double hose regulator without a safe second, and my alternate air supply is the surface (my dive site is only about 25 feet, or 8 meters deep at the deepest). The Mistral or Healthways Scuba double hose regulators have only six moving parts, and are very reliable (which is why JY Cousteau and his team used the Mistral almost exclusively). Some of my collection, such as this Sportsways Hydro-Twin, are equipped with a safe second, SPG, and LP hose for my BCD.


    Attached Files:

  8. mdax

    mdax Solo Diver

    # of Dives: 500 - 999
    Location: High Springs, FL
    I keep my regs set normally, one for each side of manifold.
    Gives me two options breathing from doubles, can isolate to stop problems.
    Usually sling stage for bailout/buddy bottle.
  9. JackD342

    JackD342 Dive Shop

    # of Dives: 500 - 999
    Location: Highland Park, IL
    If you have your heart set on one of these, Genesis sells an updated version called the Sidekick. XS Scuba also sold one until recently that included an adjustment lever. In all cases, these are on a standard LP regulator hose, they are not made to connect inline with your current BCD QC hose. (I thought I saw one like that in a catalog in the past, even thought it was XS, but now I think it is more likely I was mistaken.) I wouldn't be shocked if you find someone somewhere does make one with QC at both ends, but I would wonder about the volume of air it can deliver.

    Also keep in mind, the more adapters and parts you string together, the more awkward it becomes to use BOTH your inflator AND any inline mounted octo due to the reduced flexibility. And added weight of brass. And additional connections and O-rings to leak/maintain. Probably a big plus in favor of a combo unit Air2/Airsource/etc. instead.
    John C. Ratliff likes this.
  10. Bob DBF

    Bob DBF Solo Diver

    # of Dives: I just don't log dives
    Location: NorCal
    Already got one, rarely use it as I prefer a bungeed backup. I like diving vintage gear and trying different configurations rather than make my decisions by reading alone. I rarely get rid of gear once I purchase it, which I should try to change.


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