Electrocution at Dock

[TDJ2591]

We should all become aware of this risk. It happens all too frequently. The risk is especially high after a big storm or if a floating dock gets torn away from its mooring. I believe there were some similar deaths last year at LOTO.

http://whnt.com/2016/05/15/carmen-johns ... awareness/

[HandymanHerb]

Where is the GFI on that dock

[BoatCop]

It's not electrocution in the normal sense of the word. When there is a faulty, or no ground on a metal dock 110v power, or 110v shore tie on a boat (including on board charger) electrical current seeks ground through the water, radiating current from the metal dock or underwater appendages of the boat. (Lower unit, shaft, prop, etc)

When a person encounters the stray current, they will feel a slight tingle (not a shock)and it will cause the muscles to tense or contract (similar to a TASER, but not as powerful), although the person remains conscious. The person will sink, due to muscle contraction and drop below the current zone. They will then instinctively swim up to the surface, re-entering the current zone and it all starts over again, until they drown. The electrical current involvement won't show up in an autopsy, and the death will be mis-diagnosed as simple drowning.

If you have any power to your dock, boat or lifts, make sure it's inspected by a qualified electrician to ensure that there's no stray current. Or make sure it's turned off before allowing anyone to swim off or around the dock.

[curtiscapk]

Thanks Alan!

[Bryden24shp]

Ya, thanks! LotO has seen a lot of deaths in the last few years. Not only is it deadly, but it also takes a toll on your boat! Pits the pontoons, lower unit, anything that can conduct electricity from the water. I tested ours at LotO a few years back and got over .3 amps on my Multi tester, from my pontoons to the dock edge, about a foot away. They said it was nothing to worry about. Well, if you saw my pontoons after sitting in my slip for a month, you would beg to differ! They eventually found a bad ground at the boat house service entrance after I pushed the issue to the Condo Association committee. Its nothing to mess with!

[TDJ2591]

Thanks Alan for the explanation and great info. Having electrocution in the title might attract more readers and hopefully get the word out.

Great points Bryan. That's also really good to know and something else I had not considered.

Until those two girls died here last month, I had no idea how lethal stray current could be nor how the stray current came to be.

The Dock Lifeguard mentioned in the article is kinda pricey at around $900 but the perhaps not when we consider that it might save a life

[crookedlaker]

how do you test for stray current at a dock we have quite a few electric lifts and pumps in the channel at our lake house. I would like to test for stray current, I do have GFI on my lift power but not sure about the others

Mike

[Bamaman]

My father cut the Romex going to our dock twice by mistake--with a lawn mower. Both times he spliced the wires back without wearing his glasses--white to black and black to white. Polarity doesn't matter on a light bulb, but it really matters when a 3/4 hp electric motor is involved.

My father dove into the water to take a swim, and he felt the tingle. Unfortunately, the juice paralyzed his vocal cords. Somehow he found the strength to climb up the ladder. He then remembered seeing many fish floating around our boathouse the previous days.

The second time, we brought the boat into the boathouse at night, and saw sparks flying when our pontoon boat touched the cables holding up the rack our toon is stored on. I knew my father had cut the wire again, and it was a simple fix. You'd have thought he'd have learned his lesson.

Anyone that keeps their boat in a public boat dock or marina should be very careful and watch for stray current. This is very important.

[Bryden24shp]

Mike, I disconnected the battery cables in the boat to eliminate my boat being the source, first. Hooked up the leads from my Multi-tester to the steel dock framing and touched the other lead to my pontoon. I had it set to Milliamps, expecting maybe 50 at the most, but it went over 300, which is +.3 amps. I did it at several locations and it diminished the further from the dock, I got. I don't remember exactly what it was at the middle pontoons end cap, I want to say around 180 milliamps, I know it was just under 200. When I went to the other side, and did that pontoon to dock. it was the same, just over 300. So that told me the outside pontoons were getting more current than the center pontoon was, because they were closest to the dock framing. And when we pulled it out, you could see the pitting in the outer pontoons was more than the center. Nothing on the prop, because I always tilt the L/U out of the water, when slipped. I also tapped onto a few other pontoons in the same boat house, they were more, the closer I got to the walkway. That's how I got the Associations attention.