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CESA - why? I'll never run low on air!

Discussion in 'Basic Scuba Discussions' started by Rick Murchison, Mar 29, 2007.

  1. Rick Murchison

    Rick Murchison Trusty Shellback Staff Member ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: Gulf of Mexico
    There have been a couple of threads on the CESA lately, with several folks declaring it an unnecessary skill, because with "proper" diving skills you'd never need it.

    Here are just two of many examples (I ain't pickin' on you two; y'all just said it clearer and in fewer words than the others :) )
    It seems many folks feel the only reason anyone would want to do a CESA is in an out-of-gas situation, and since any good diver will never, ever be in that situation then the CESA is not a necessary skill.
    I'd like to revisit that.
    What is a "Controlled Emergency Swimming Ascent" and what are some of the reasons we might want to do one? The CESA is simply the means to make an emergency ascent to the surface. Are there reasons we might want to do that other than being low on, or out of gas? I say "Absolutely!"
    Because there are reasons other than "gas planning and buddy skills" that might lead to the CESA decision, the ability to do a safe CESA in the face of great stress, pain or distress or injury is an essential skill for all Scuba Divers.
    What are some of those reasons?
    1. CVA. A cardio-vascular accident - a survivable heart attack, stroke, etc often leaves little time for decision-making and action before complete disability to do anything useful, like informing a buddy you're in distress. An immediate CESA could give you a chance to avoid certain drowning, and to get to help on the boat in time to save your life. Every second counts.
    2. Bleeding. A severe cut or bite can start the blood-loss clock; your ability to do anything may be short lived and a CESA while you can do something can once again get you to a more survivable environment.
    3. Severe pain. Whether it be some internal source (sudden burst appendix or ovarian cyst or kidney stone etc) or from injury (poisonous spine, sea wasp etc), once again, pain of this magnitude may severely limit your time of useful consciousness; time to topside help is of the essence and a CESA may be your best choice.
    4. Impending panic. It is far, far better to do a CESA while still in control than to allow panic to take over and do a UPA ("Uncontrolled Panicked Ascent"). Indeed, just knowing you have the option and are competent at the CESA can go a long way in keeping under controll in the first place.
    The CESA should remain in the syllabus at the entry level; the ability to conduct a safe, rapid emergency ascent without danger of an overexpansion injury should be ingrained to the point of "automatic" in every Scuba Diver, even those who will never, ever run out of air. IOW, I think the CESA is as important in a Scuba Diver's "tool kit" as a wrench is to a mechanic.
  2. Diver Dennis

    Diver Dennis Solo Diver

    Thanks for the well thought out post Rick.
  3. Karibelle

    Karibelle IDC Staff Instructor

    In those instances, assuming you still have air, you think the CESA is a better choice than a normal ascent? What am I missing?
  4. LetterBoy

    LetterBoy he who lacks empathy ScubaBoard Supporter

    # of Dives: 100 - 199
    Location: The edge of the earth.
    So I wonder what they do in DIR if you have one of the above incidents. . .
  5. drbill

    drbill The Lorax for the Kelp Forest Scuba Legend

    # of Dives: 2,500 - 4,999
    Location: Santa Catalina Island, CA
    Good points, Rick.

    There are only three times over 45 years that I've had to do a CESA.

    The first one was back in the 60's when we didn't have SPG's, just J-valves. I had pulled a tank off the "filled" rack and descended to 90 feet only to find it was an empty. Somehow the J-valve had been pulled in the descent. My buddy experienced the same problem. The CESA was uneventful.

    The second doesn't really count. I was on my ascent (along a slope) at the end of a dive and saw something I just HAD to film. I kept shooting until my tank ran dry, and ascended but only from a depth of 15 ft.

    The third illustrates another valid reason for knowing the skill that has nothing to do with gas management. I had descended to 70 ft (without my pony... bad on me) and suddenly air flow from my tank ceased shortly after I exhaled my last breath. I did an 80 sec CESA. We discovered that the tank valve on a full tank had become clogged, stopping air flow.
  6. Diver Dennis

    Diver Dennis Solo Diver


    If I was rapidly losing consciousness, I would not be doing a normal ascent. That could be happening in any of those examples.
  7. DeepBound

    DeepBound Solo Diver

    # of Dives: 200 - 499
    Location: Ottawa, Ontario
    It's so refreshing to read a logical thought-out post about CESA.
    Given that this is a useful skill, how can it be practiced safely?

  8. fppf

    fppf Manta Ray

    # of Dives: 200 - 499
    Location: Buffalo NY
    Good post Rick.
    CESA is also another way to reinforce to a new diver NEVER to hold your breath.

    There are many reasons someone would need to make an accent. There are also equipment failer modes that would cause an uncontroled accent.

    In any event, if you hold your breath, you may as well just stay down there.
  9. Karibelle

    Karibelle IDC Staff Instructor

    Would you be ascending more quickly than a "safe ascent rate"? if you are, then you're not doing a CESA either.
  10. Steve50

    Steve50 Master Instructor

    # of Dives: I just don't log dives
    Location: USA - around the middle
    I agree - you may choose to make a more rapid than normal ascent - but why not breathe normally.

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