View Full Version : Electric Shock Drowning - 42 fatalities

07-25-2012, 08:11 PM
A good friend in Texas who races boats mailed a note about this yesterday -
I was up all night reading everything I could fine and gathered most of the critical links I could fine
to share with you all so no one ever has to deal with this.

From now on - I wouldn't go near a craft using shore power without checking for voltage leaking while plugged to shore power.

The simple main tool for checking - HIOKI 3280-20

The current can be so small - yet paralyze anyone in the water within range of the source.
2 VOLTS PER FOOT is considered lethal.
Less than 100 Milliamps - is dangerous - when 1000 Milliamps barely fires up a lightbulb.

NEVER Dive in after anyone who looks unconscious - The source is more than likely nearby - CUT the power source to that craft immediately.

NEVER hook up two crafts with extension cord coming from an onboard generator with unapproved devices.

PAY ATTENTION - to dead fish - birds near a craft - more than likely were electrocuted.

POWER LIFTS - by 120v - DIY Guys - Be Darn Careful to the MAX how it was done.

EXample -
2 dogs jump in from the owners boat -
Wife notices distress - jumps in - Husband jumps in to save Wife - They both died.
Caused by faulty light switch on craft nearby.

Years ago - a friend wanted me to install a power source on aluminum dock & lift so he could keep his pontoon batteries charged.

I refused - Instead - I used 10g underground cable with connections near the craft to connect jumpers with Anderson Quick connects to the batteries.
The other end 150 feet on shore is connected to the 12v source from Battery Charger on Ground fault circuit.
This is so much easier to monitor batteries from shore - than walking out to the craft -
tripping on extension cords at night - falling in with hot AC following you in.

Have a Safe Summer..

Hot Docks, Hot Boats and Electric Shock Drowning

THIS video link was reposted/fixed, but is unlisted - http://www.youtube.com/watch?v=O7-s_mdEPb0


An undetected AC ground fault which produces a water path current in salt water may not create enough current density to affect a swimmer, even with a defective bonding conductor (ground).

Because of the much higher resistance of fresh water, however, the swimmer becomes the fault path conductor when the boat or dock ground is missing.

A voltage rise will occur on the underwater gear of the affected boat and cause a paralyzing low level current to flow in the swimmer.

Harbor Marine has cataloged over 115 "electric shock incidents" in marinas which have resulted in 42 fatalities (list available).


(Electric Shock Drowning Incidents – Marinas)

Google Search - Electrical Shock Drowning

07-25-2012, 08:47 PM
Thats all GREAT information that people really never think about.

07-26-2012, 08:59 AM
Some great info. Thanks for compiling it.

07-26-2012, 10:22 AM
This makes me a little concerned...

We have an aluminum floating dock, with 120v power for lift, lights etc.

If you are sitting on the dock, with your feets in the water, and you touch something aluminum on the dock, you get a little buzz. Feels sorta like a 9v batt does on your tongue if you can remember being young enough to do that.

07-26-2012, 01:56 PM
Umm, get an electrician out there post-haste?

07-26-2012, 05:21 PM
As an electricain I've read tons of stories on this topic. Mostly on the Mike Holt site. Search that if you want more reading. But marinas scare the hell out of me. I see enough shoddy work on land by electricians, nevermind work on piers by non professional installers.

07-26-2012, 11:22 PM
This makes me a little concerned...
with your feet in the water,
you get a little buzz. Feels sorta like a 9v batt does on your tongueI know, I felt this as well as a kid when my hand was in the water, and I wasn't sure what to think, but I suspect it was the dock light, and never dove in.

07-26-2012, 11:40 PM
For some reason-this video link is unlisted I just discovered-hopefully it will work here.

05-03-2016, 05:49 PM
There was a recent fatality on our lake a few weeks ago (see http://whnt.com/2016/04/18/taking-action-preventing-electric-shock-drowning/) due to Electric Shock Drowning (ESD). This story has me worried about it happening at or near my dock. I feel good about the wiring on my dock after doing quite a bit of research and having it examined. However, I am not so certain about the neighboring docks. Plus, they may all be good now, but how can one be certain about tomorrow (after corrosion, storms, other damage, etc.)?

To that end, does anyone have experience with this device? https://shockalarm.com/

Are there any other alarm alarm devices out there?

05-03-2016, 10:59 PM
This was a tragedy. There is a Facebook page for smith lake that has some good info. I will post a link to the group. There are a few posts in the group about it. Apparently, Cullman electric and maybe Alabama power will install a voltage isolator that's supposed to keep a shock from occurring. We had our dock on smith wired this year by an experienced electrician. We have breakers at the walkway and gfci circuits. Even with this, we still turn off power to the dock when the kids are swimming. We also make them wear life jackets anytime the are near the water. We are in a slough but the water is about 60 ft deep at the end of my dock. It would not be hard to get lost down there...