Electric Shock Drowning: A Hidden Danger In Fresh Water

Discussion in 'All Things Boats & Boating' started by Proteus, Jan 23, 2013.

  1. Proteus
    Joined: Mar 2007
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    Proteus Junior Member

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  2. BPL
    Joined: Dec 2011
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    BPL Senior Member

    Scary.
    Would you notice the electrical leakage rowing around the marina in a metal dinghy?
     
  3. CDK
    Joined: Aug 2007
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    CDK retired engineer

    There is a lot of electrical leakage current in every marina, caused by shore power cables. dissimilar metals and "Mercathode" units. All of these can be easily measured with fairly simple equipment, but go unnoticed when you are in a metal dinghy. In fact the aluminum dinghy itself causes a voltage offset between you and the water, also too small to be felt.

    The Huffington Post article is a little bit of truth diluted with a lot of rubbish, what I call another "Loch Ness story".
     
  4. El_Guero

    El_Guero Previous Member

    CDK, where is the truth; and what is the fiction?
     
  5. CDK
    Joined: Aug 2007
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    CDK retired engineer

    First of all: electrocuted people do not talk to newspaper journalists, do not pose for a camera or write down what they experienced because they are dead.
    So anybody with firsthand experience received an electrical shock of unknown severity, enough to get exited about but not nearly enough to loose consciousness or get into coma. I know because I've been there several times.

    It is possible to electrocute someone in the water if you set your mind to it, like throwing a live wire to a swimmer and disabling whatever safety device is part of the circuit. Another possibility would be an accident, like a welder stumbling over his transformer, grabbing the cable while falling overboard.

    A swimmer approaching a live wire in the water must be very, very curious and ignore tell tale signs until he/she gets muscle spasms and cannot pull back.
     
  6. Ike
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    Ike Senior Member

    I have known Kevin Ritz since his son died. Working in the USCG Office of Boating Safety I had to deal with the families of the deceased, and let me tell you there is no answer that is sufficient to the question "why didn't you do something to prevent this?"

    Electric Shock Drowning is very real and every year people are killed by it.

    We are not talking DC here. We are talking about AC leaking into the water, usually from bad marina wiring, but it can come from a boat. I have never addressed the issue of a metal boat floating nearby, but I suppose it could happen. I have investigated accidents where persons were shocked by touching metal railings on boats and on the docks when AC was leaking into the water.

    There have been people who survived because they realized something was wrong as they swam into the zone of electrified water and managed to back away. A few have been pulled to safety by bystanders who realized what was happening and used some non conducting device to rescue them. Unfortunately some people have died trying to rescue the victims because they dove into the water.

    The best rule is "Don't swim around marinas"! If you suspect this problem have an electrician check it out. There are meters that can measure the level of current in the water. But definitely tell your children do not swim at the marina. If they will, get your marina to put up a sign, NO SWIMMING.
     
  7. michael pierzga
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    michael pierzga Senior Member

    Ive never really thought about it. I do all my underwater maintenance at a marina. Luckily this is sea water.

    Prominent signs and boater education is logical.

    Is there a commonly available sensor, alarm, warning light that can be fit to warn of electric leaks ?
     
  8. Ike
    Joined: Apr 2006
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    Ike Senior Member

    You should have an RCD (Residual Current Device), pretty much the same as a GFCI on all power outlets on the dock. They are required in Europe, but not here. NFPA requires GFCIs just about everywhere, except marinas. That is why ABYC went with the ELCI for boats. They can't step in NFPA's turf but they can for the boat so an ELCI does basically the same thing, detects leakage current and shuts off the circuit. But that only protects the boat, not the leakage from the marina. You can use a clamp meter like this http://www.fluke.com/fluke/usen/com...s/ArticleCategories/Clamps/Leakage Basics.htm to check for leakage current. There are other brands.

    Good article here http://www.boatquotes.com/abyc.htm on how to do this.
     
  9. michael pierzga
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    michael pierzga Senior Member

    Sure


    Ive got all that stuff....does it work...does the neighbors work ?

    Then consider very small craft with no AC electric system, or two boys with a fishing rod on the dock who may jump in the water for a cool off.

    Extra regulatory vigilance and boater education around fresh water marinas sounds logical.
     
  10. CDK
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    CDK retired engineer

    "don't swim around marinas" is very sound advice. The dangers of electrocution are very remote, but the staggering amount of E. Coli and Salmonella bacteria alone justifies a short trip to an uninhabited bay for underwater maintenance.
     
  11. michael pierzga
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    michael pierzga Senior Member

    Yes indeed and if you must go in the water be extra vigilant and avoid cutting yourself on marine growth. Nasty infections develop.... needing many injections of miracle drugs to cure.

    The local harbour divers wear womens stockings over their heads to protect against infectious junk entering their ears.
     
  12. Proteus
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    Proteus Junior Member

    Scary, indeed!!! I'm glad this is not such a big issue in saltwater. Nevertheless, the excess damage done to fasteners because someone's boat isn't bonded correctly is really bad. This also seems to be an issue with some houseboats that are not bonded correctly from what this story has to say. Whose really liable for it still seems unclear to me because the houseboat was not really all that far off the dock. It could be the manufacturer, the boat owner or the marina. http://www.campbellsville.com/wp/20...electrocutiondrowning-at-emerald-isle-marina/

    I picked that article up at this facebook group, Electric Shock Drowning
    http://www.facebook.com/#!/groups/117494761627517/?fref=ts
     
  13. MikeJohns
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    MikeJohns Senior Member


    Peculiar to US and countries with similar distribution systems and no ELCB devices.

    Europe and Australia require earth leakage circuit breakers both onboard the vessel and in the marina supply outlets. This works very well with Multiple earthed neutral AC distribution to protect people.

    Pure fresh water is actually a very good insulator and salt water is a good conductor. In between there is a danger zone where the human being is a better conductor than the poorly conductive ( lower number of ions in solution) water.
     
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  14. El_Guero

    El_Guero Previous Member

    I think people did not understand what you wrote .....

    That is true for many rivers as well ....
     
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  15. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Yes El_Guero, that is also true, especially in crowded areas and countries without environmental legislation.
    The good thing is that such "fresh" water also contains a lot of chemicals, making it as conductive as seawater.
     
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