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Thread: 1 BCD 2 divers: Is it okay?

 


  1. #61
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    Quote Originally Posted by KD8NPB View Post
    At 13 ft, we're looking at a grand total of 5.5 psi of water pressure meaing a total of 1.37 ATA. That would put air density at about 0.0745 lbm/ft3, which is a less than 1% increase of air density from sea level.
    The pressure at that depth is not the issue. It is the change in pressure as you ascend that matters.

    That is based on Boyle's Law, mathematically represented as V1P1=V2P2.

    So let's start with a volume of 1 at 1.37 ATA and see what happens when we go to the surface. That makes the formula 1 X 1.37 ATA = V2 X 1 ATA. To solve for the volume at the surface, we have to divide 1.37 by 1, meaning the original volume of 1 will expand to 1.37. This shows us that the air in the diver's lungs will have increased in volume by more than 1/3 by the time he gets to the surface. That is more than enough to cause a fatal injury.

    Of course, the same thing could happen to even the most seasoned instructor. If that happens, there will likely be a lawsuit, and if the instructor is following accepted practices for instruction, that lawsuit will fail. Even if it succeeds, instructors are required to carry liability insurance that will cover them. If it happens to you, you are not an instructor, and you are not following accepted practices. The lawsuit will succeed, and you will not have the required insurance to cover it.
    John Adsit
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    I am just in complete shock now. You really think you are an instructor because you saw someone do it once. This is akin to me teaching someone how to skydive because I read a book on it once and did a tandem dive.
    *This space for rent*
    Quote Originally Posted by Dbmata View Post
    I don't know whether to worship you, or hunt you to display you over my fireplace.

  3. #63
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    Quote Originally Posted by Incognegro View Post
    When I did my Deep certification the instructor did a share air with me while another student finished his navigation requirements for AOW, because of anxiety at the beginning of the dive I would use alot of air and get more relaxed later. I had enough air in my tank to ascend and do a safety stop. Was this the wrong thing to do, should he had let me get low instead of letting the other student complete his task?
    ... if the other student had a problem that required assistance, who was going to assist him? How?

    An instructor must, above all else, always be in a position to assist a student who has an unexpected problem. Often times when a problem occurs, assistance is needed immediately ...

    ... Bob (Grateful Diver)

    ---------- Post added April 26th, 2012 at 09:19 AM ----------

    Quote Originally Posted by JamesK View Post
    I am just in complete shock now. You really think you are an instructor because you saw someone do it once. This is akin to me teaching someone how to skydive because I read a book on it once and did a tandem dive.

    ... it's more like you offering to tandem skydive with a complete novice after having only done it once ... and him not at all.

    But hey ... what can go wrong ... after all ... ya both read the book ... and you're only jumping from 1,000 feet ...

    ... Bob (Grateful Diver)
    It was just below freezing and snow was falling steadily. As we stepped toward that portal separating a cold and dreary world from the tranquility and wonder of another dimension teeming with life and color a passer-by shook his head and muttered "crazy". Poor fool. If he only knew. (Airsix)

    Come visit me at http://www.nwgratefuldiver.com/

  4. #64
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    Quote Originally Posted by JamesK View Post
    I am just in complete shock now. You really think you are an instructor because you saw someone do it once. This is akin to me teaching someone how to skydive because I read a book on it once and did a tandem dive.
    I would rather he learn from me in a controlled setting, along with learn the good & bad of scuba, than go die in a certified Carnival Cruise Discover Scuba course.

    Quote Originally Posted by boulderjohn View Post
    Of course, the same thing could happen to even the most seasoned instructor. If that happens, there will likely be a lawsuit, and if the instructor is following accepted practices for instruction, that lawsuit will fail. Even if it succeeds, instructors are required to carry liability insurance that will cover them. If it happens to you, you are not an instructor, and you are not following accepted practices. The lawsuit will succeed, and you will not have the required insurance to cover it.
    Liability is not a concern.

  6. #66
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    Quote Originally Posted by JamesK View Post
    I am just in complete shock now. You really think you are an instructor because you saw someone do it once.
    Actually, he assumes he is better than an instructor.

    Quote Originally Posted by KD8NPB View Post
    I would rather he learn from me in a controlled setting, along with learn the good & bad of scuba, than go die in a certified Carnival Cruise Discover Scuba course.
    JamesK likes this.
    John Adsit
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    He must have stayed at a Holiday Inn ,he has all the answers.

    Too bad the person he is going to "train" doesn't see this thread.
    JamesK likes this.

  8. #68
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    Quote Originally Posted by KD8NPB View Post
    At 13 ft, we're looking at a grand total of 5.5 psi of water pressure meaing a total of 1.37 ATA. That would put air density at about 0.0745 lbm/ft3, which is a less than 1% increase of air density from sea level.
    As others have already illustrated, the issue of pressure in relation to lung over-expansion injury stems from the change in pressure, not its absolute.

    People have died in swimming pools on scuba.. ascending from kneeling in the shallows to standing at the surface. Shallowest recorded incidence of severe lung trauma was recorded on an ascent from 0.3m to the surface.

    Given the split second in which a fatal incident could occur... what's your 'expert' strategy to ensure that you could prevent it? Qualified instructors deal with this risk to students, day-in / day-out.

    Quote Originally Posted by KD8NPB View Post
    No progression into deeper water will be made unless he can show competency at mask clearing, regulator retrieval, and buddy breathing in the 4 ft shallow end. We'll do progressions with that. Mask on, 5mm gloves on, mask off w/ gloves, blindfolded w/ gloves (only in the shallow end, where simply standing up takes you out of the water). The things I'll look for are open airways (blowing bubbles) and calm actions. If any panic is shown, we'll suspend it right there.
    This is a fantasy, right? You are SERIOUSLY assessing yourself capable of teaching scuba, when you have virtually zero practical experience of doing the activity yourself?

    You need to arrest this. Go visit a decent instructor and ask them to 'put you through your paces'. I'm sure there'll be a volunteer or two here on Scubaboard. The average professional instructor completes 3x your total logged dives in an average month... many do substantially more.

    I don't care what you think about your competence as a diver - I know you could be pushed easily to meltdown in 5 minutes. That's a promise.

    Quote Originally Posted by KD8NPB View Post
    But we need to focus more on real-life skills.
    There is no 'we'. There are professional instructors.... and there is you... a noobie. If you've not noticed, you're in a minority of one... and rapidly losing any credibility on this forum.

    You ascertain that you have some intelligence... so perhaps it's time to engage that grey matter and start listening to people. The ability to appreciate the limitations of your knowledge and formulate an effect self-appreciation being several key defining factors of intelligent behavior.

    Quote Originally Posted by KD8NPB View Post
    My $.02 about instruction.
    Thanks, but it's not quite worth that much.

    Quote Originally Posted by KD8NPB View Post
    Would anything change if I had an instructor certification? No,..
    Plenty would change as you gained experience. That's another promise. If it didn't, you'd never get past the door on a DM course, let alone instructor.

    Personally, I don't give a toss about your self-delusions.... but what you're suggesting/advocating has a direct impact on the safety of others, who may be naive enough to believe your bravado. For their sakes... it's time you woke up and smelled the coffee.

  9. #69
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    Quote Originally Posted by KD8NPB View Post

    Liability is not a concern.

    Unless he's your kid, your spouse is dead, and there are no other members of your immediate family capable of suing you, liability is always a concern.

    Moreover, that's only civil liability. I will reiterate that I firmly believe you would have reason to fear criminal liability.

    In my state, at least, this would in my mind clearly be an open and shut manslaughter case.

    609.205 MANSLAUGHTER IN THE SECOND DEGREE.

    A person who causes the death of another by any of the following means is guilty of manslaughter in the second degree and may be sentenced to imprisonment for not more than ten years or to payment of a fine of not more than $20,000, or both:
    (1) by the person's culpable negligence whereby the person creates an unreasonable risk, and consciously takes chances of causing death or great bodily harm to another;
    JamesK likes this.
    If we were logical, the future would be bleak, indeed. But we are more than logical. We are human beings, and we have faith, and we have hope, and we can work.
    -- Cousteau


  10. #70
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    Quote Originally Posted by Dbmata View Post
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