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What You Need To Know About Electric Shock Drowning (ESD)


Slip 866 Sunset Marina Byrdstown Tn

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    mvnmvn Member, Moderator Posts: 744 mod

    Excellent read Boomer.  Scary sh!t.  I do not have shore power but obviously find myself around many docks that do.  This article has raised my awareness.

    Many thanks.

    Mark

    Good,  fast,  cheap.... pick two. 
    2019 MTX20 Extreme

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    TikiHut2TikiHut2 Member Posts: 1,431 ✭✭✭✭✭
    edited July 2013
    Seaworthy and BoatUS cover some great stuff. I hoped somebody would post that. It certainly might save a life. It's astounding how many people are lost to ESD in fresh/brackish water every year. Thanks Boomer.

    Mike


    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
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    rmrstlmormrstlmo Member Posts: 225 ✭✭✭
    Very good article but it didn't mention generators.  I'm guessing it would be good practice to not let anyone swim while the genny is running.

    Ray

    2006 390

    Previous 2000 340

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    BabyboomerBabyboomer Member Posts: 918 mod
    rmrstlmo said:
    Very good article but it didn't mention generators.  I'm guessing it would be good practice to not let anyone swim while the genny is running.
    I think Carbon Monoxide would be the safety factor on a Genny

    Slip 866 Sunset Marina Byrdstown Tn
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    TikiHut2TikiHut2 Member Posts: 1,431 ✭✭✭✭✭
    edited July 2013
    Ray may have a point but I wouldn't be qualified to confirm it. It'd be a good question to pose in an email to Seaworthy.

    Danger from either CO or ESD would be reason enough to reconsider swimming with a genset running but both risks will have me thinking about who's in the water from now on, especially ESD when we're in freshwater (although rarely). One of the links below cited research that shows as many as 13% of all the boats in a typical freshwater marina are emitting potentially lethal amounts of electrical current at any given time.

    Here's the USCG Carbon Monoxide CO brochure  (LINK)

    Here's the Not for profit ESD public awareness page with addl resources (LINK)

    Here's the ESD in-depth research grant data funded by the USCG (LINK)

    Plenty of reading, some of it heart wrenching and definitely sobering regarding our level of responsibility as the captain to keep our crew and passengers safe. Great thread Boomer.
    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    People are amazed when you tell them about this and why to never swim in a marina.

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    ruwallydogruwallydog Member Posts: 92 ✭✭
    Totally freaked out. Everyone including my family swims at our marina all the time.

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    TonyWalkerTonyWalker Member Posts: 744 ✭✭✭

    I guess when the ground (green wire) was brought aboard the boat, this is what made it a danger.  In the 50's we had the usual two wire 110 Volt service circuit and it was not ever an issue that I was aware of.

    Tony

    Salt Shaker 342

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    TikiHut2TikiHut2 Member Posts: 1,431 ✭✭✭✭✭
    edited July 2013
    ...that you were aware of (luckily). Tony, unless I missunderstand you, with the addition of a ground/bond wire it's the other way around, far safer.

    I'm not an engineer so my lame explanation may be vague...The bond/ground wire is a safety feature that allows a safe path back to ground for any appliance that has a fault. It's the event where BOTH failures exist that people can die. The bond/ground fails AND an appliance has a short of some sort. The unsuspecting swimmer(in the case of ESD) who enters the area then experiences the silent disparity in voltage running through their body as that current seeks a quick path back to ground.....ESD usually follows as they become paralyzed by the nature of A/C current. a DC fault is far more survivable.

    The much maligned GFCI outlet/breaker has saved many many lives by measuring for fault/unequal current and shunting the power in millseconds. There's been discussion of mandating these at every dock terminal like many foreign country's but the US has been reluctant due to the sensitivity to tripping and the inconvenience (as if helplessly watching someone drown isn't)

    Anyone should feel free to correct any misstatement regarding my attempt at a description. Thanks, Mike
    2004 FV270, 300hp 5.7 350mag MPI Merc 305hrs, 2:20 Bravo3 OD w.22p props, 12v Lenco tabs, Kohler 5kw genset, A/C, etc.etc...
    Regular weekender, Trailer stored indoors, M/V TikiHut, Sarasota, Fl
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    TonyWalkerTonyWalker Member Posts: 744 ✭✭✭

    Tiki,  What you said is correct.  What I was thinking was that in the old days with wood boats, the neutral was isolated from the boat ground as it is today.  Other than the engines, propellers and perhaps the gas tanks, I am unaware of any intentional connections between appliance frames.  Since I am thinking there was no electrical path from the boat ground to shore, a fault would be isolated from all that part of the system.  I do not remember any interwiring between the frames of any equipment.  I could be wrong.

    Interesting thing about the GFI plugs, they occasionally start a fire.  My friend in Palmyra had his house almost completely destroyed by such a GFI outlet.  A guy I know in the contract electronic assembly business will not touch any part of their manufacture because of the associated liability.

    Tony

    Salt Shaker 342

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    TonyWalkerTonyWalker Member Posts: 744 ✭✭✭

    I will add a couple more things about the '50's.  The shore power cord was a simple two wire extension cord rated for 15 amps that could have been obtained from any SS Kresge.   Does that date me?  Also the only items that was powered up by this two wire system were a few 110 two prong electrical outlets through out the boat, the house battery charger and the domestic water heater.  Simple in those days.  No electrical circuit or connection was closer than a few feet to the few items that had electrical exposure to the water.  Engines and props are the only items that come to mind.

    Someone may have different memories from the boats of the 50's than me.  Please post anything that contradicts what I think I remember.

    Tony

    Salt Shaker 342

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