ESD Electric Shock Drowning/ No Shock Zone

Aqua Puttana

Poly - Thread Finder
With on the water activities often being a part of RV/conversion, ESD is something which I feel makes sense to highlight here.

I really don't know what to suggest as a reasonable response for ESD. Certainly I still go into the water to do work on boats when necessary, but as much as possible I avoid doing so around metal floating docks and moored boats which are an obvious floating RV. (Floating RV's have more electrics.)

At one time I would often just jump off the dock into the water to cool off after sailing. I no longer do that around metal floating docks that have mounted electrical service pedestals or lighting, or around docked boats with shore power connected.

Mike Sokol has also been active in providing RV related No Shock Zone and some ESD information.
The Shocking Truth About RVs

This is worth reading. vic

The Gowrie Safety Report
Gowrie Group

Understanding Electric Shock Drowning

Soon boats will be launched, kids will be swimming, sailing programs will start, and marinas will be in full operation. With this in mind, now is a good time to increase your knowledge of Electric Shock Drowning (ESD). Many people have never heard of ESD, and those that have typically don’t realize the common situations that can be putting people at risk for ESD.

These common waterfront scenarios seem innocuous, however ESD should be considered as a risk in each. This Gowrie Risk Report helps explain why.

• A sailor cleaning their boat’s bottom before a weekend race.
• A powerboat owner swimming to inspect a new propeller while tied to the dock.
• A marina employee falling off a new dock.
• A boat owner climbing out of the water using the metal ladder on their swim platform.
• A group of kids jumping off a marina dock and using the marina’s emergency escape ladders to get out.
• An orange extension cord draped across a lake dock to charge a ski boat’s battery.

What exactly is Electric Shock Drowning? ESD is caused by alternating current (AC) flowing through fresh water encountering a human body. The current tries to pass through the body and causes skeletal muscular paralysis, which ultimately results in a drowning. The electricity tends to enter the water from an electric fault from a nearby dock or marina’s wiring, or from a boat that is connected to a power supply. Often, the electric fault occurring from the boat is intermittent and only leaks current into the water when a switch is flipped and an electrical device cycles on.

Why have I never heard of this? ESD is a relatively new problem, given that 20 years ago very few docks were powered. Given the prevalence of electric boat lifts, lights, and shore-power connections on docks of all sizes and at nearly every marina, the risk of ESD is real today. In the 80’s it was commonly considered safe to dive off a dock without a thought of ESD. Today, the common summertime activity of swimming off a dock or diving under a boat can result in a tragedy.

Fresh vs. Salt Water. While ESD can occur in salt water environment, , the risk is much higher in fresh water bodies of water (lakes, ponds, rivers) because of differences in conductivity. Salt water naturally has a high conductivity and low resistance, so leaking current in water tends to go around a human body to stay in the low resistant salt water. In fresh water, which has low conductivity and high resistance, the electrical fault or current seeks a path of lower resistance to get back to its source – and a human body can serve as this low resistance path. Fresh water is nearly 70x more resistive than salt water.

Tiny Amounts can be Deadly. In fresh water, minute amounts of leaking alternating current can kill. Just 15 milliamps (mA) can cause skeletal muscular paralysis, while 100 mA can cause death with a few seconds. (Captain David Rifkin, USN retired)
Faulty Wiring. Many times, it is later discovered that the leaking current in an ESD resulted from faulty wiring done by an amateur, which did not meet marine code. The marine codes in play are NFPA 303 (Fire Protection Standard for Marinas and Boatyards), NFPA 70, and National Electric Code 555 (NEC). Often boats not wired in accordance with standards set forth by the American Boat & Yacht Council (ABYC) can be a source of AC leakage. Ed Sherman, a certified master technician and Vice President and Education director at the ABYC shared with Gowrie Group his recommendations related to marine wiring and reducing ESD risk. "One of the most common sources of AC ground faults on boats are on board water heaters that have developed electrical leakage in their heating elements. This is not enough to trip a fuse or circuit breaker, but it is definitely enough to present a potentially dangerous level of electrical current into the water around a boat. Boats that have had electrical repairs performed on them by land-based electricians are also often the cause of leakages. Non-marine electricians will often innocently wire boats as they would a home, without knowing that the wiring configuration requirements on boats is quite different from homes. I strongly recommend that you only have your boat wiring performed by and checked by an ABYC certified marine electrical specialist."

Preventing Electric Shock Drowning (Source: ESD Association)

• Don’t swim in or near freshwater marinas, docks or boatyards energized with 120-volt AC power.
• If you are a boat owner, have your boat inspected by an electrician with current ABYC
(American Boat and Yacht Council) Electrical Certification or by an ABYC Certified Technician.
• If you keep your boat at a marina, talk to the marina owners or operators about the danger of electric shock drowning. Ask if GFCI’s are installed on all shore power pedestals and on all marina wiring circuits. Ask if their marina is regularly inspected by qualified electricians who are familiar with National Fire Protection Association Codes: NFPA 303 and NFPA 70.
• Tell others about the danger of Electric Shock Drowning.

These additional resources provide valuable details about ESD:

• Electric Shock Drowning Prevention Association

• "Does Death Lurk Below," Boating Magazine article

• "Preventing ESD at Marinas & Yacht Clubs," by Ace Insurance

• "ESD, What You Need to Know," technical article by ABYC Master Tech, Ed Sherman

Gowrie's Safety & Loss Prevention insights are created by Kellie Crete and Whitney Peterson.
Kellie manages Gowrie Group's Safety & Loss Prevention practice area and has more than 25 years of experience in safety and loss control, and specializes in advising the marine industry and other niche segments of the commercial marketplace. Kellie is an OSHA authorized instructor. Whitney Peterson is Gowrie Group’s VP of Marketing. She is responsible for client communications, branding, strategic partnerships, and outreach.

For more information,,, or

Gowrie Group. Always on Watch. As one of the nation's Top-50 independent insurance agencies, Gowrie Group provides total risk management services to individuals and businesses with complex insurance needs. Gowrie Group offers comprehensive insurance solutions matched with trusted advice and a commitment to service excellence. Gowrie Group’s portfolio of offerings includes commercial, home/auto, equine, and yacht insurance, as well as employee benefits solutions. The company's 140+ professionals service clients across the US from offices in Westbrook CT, Darien CT, Marshfield MA,
North Kingstown RI, and Newport RI. For more information, or 800.262.8911.

Gowrie Group Risk Report: Understanding Electric Shock Drowning.
Sources: Electric Shock Drowning Organization, Ace Insured, Boating Magazine, ABYC, Ed Sherman.
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2005/2006 leisure travel
Thank you.I too had never heard of this.But I also have never read about a fatality from this.It seems folks would be getting fried every day.How common are such deaths?

Aqua Puttana

Poly - Thread Finder
Thank you.I too had never heard of this.But I also have never read about a fatality from this.It seems folks would be getting fried every day.How common are such deaths?
It's really not that uncommon. Some deaths/drownings do not include shock during investigation conclusions, but shock still may have been involved. I recall a story (last year?) about a couple teen girls suffering Electric Shock Drowning after swimming off a dock.

FoxNews said:
<snip>Electric shock drowning has caused more than 100 deaths across the country in recent years, said Ritz, who is a certification instructor for the American Boat and Yacht Council, which develops safety standards for boats. No federal agency tracks the deaths, he said.

In many cases, a victim's autopsy shows no signs of electrical injury, so it's likely that more electric shock drowning deaths go unreported, said Molly Hall, executive director of the Energy Education Council, a national nonprofit based in Springfield. And if witnesses aren't present, officials often stop their investigation and point to drowning, Hall said.

Another comment.

Electric Shock Drowning - 42 fatalities - TeamTalk - MasterCraft

Mastercraft said:
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 -

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
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Aqua Puttana

Poly - Thread Finder
How does one use this multimeter to check for voltage loss from a marine cable into water?
I'm no expert on this, just the messenger.

I'm not certain that a multimeter would be effective. The danger can include a voltage gradient in the water. I don't know how that could be tested with the multimeter probes. The meter probes probably wouldn't have enough conductor surface area to get a reading.


Aqua Puttana

Poly - Thread Finder
Very sad news, but it is on topic and may increase awareness.

Grieving Parents Warn Against the Dangers of Lake Electricity After Daughter Is Killed

Carmen Johnson, 15, was a high school cheerleader who enjoyed life, got good grades and loved to be on the water.

It was a terrible accident on the water that took Carmen’s life on April 16, and her parents, Jimmy and Casey, are warning others about the potential dangers.

The Johnsons say Carmen, their youngest child, was electrocuted while swimming in the lake behind their home. Her parents told ABC News that the electrical currents came from rusty electrical work at the dock in their backyard.

It’s called electric shock drowning -- when a current, usually from a short circuit in the wiring of a dock, marina or boat, spreads through the water, and someone in the water is shocked and drowns.

Carmen's father, Jimmy Johnson, said he initially thought something was pulling Carmen down into the water.

“I was in a position where I could have saved her if it would have been anything but electrocution in the water,” her father said.

In fact, Jimmy and his son, Zach, both jumped into the lake to try and save Carmen. They were nearly killed themselves.

“It was instant. It just grabbed hold of me,” Jimmy Johnson said of the electric shock.

Zach said, “It felt like your arm or leg is asleep and it hurts to move, and you can’t move, but it’s your entire body. And you’re trying to tread water but can’t swim."

The two were saved when Casey Johnson ran and turned off the power switch. A friend who had been in the water with Carmen was also injured but she survived.

In Missouri in 2012, Alexandra Anderson, 13, and her 8-year-old brother, Brayden, died while swimming near their family’s dock. Their mother has been lobbying state lawmakers to make docks safer.

Several states are now calling for circuit breakers near the water, and for the kinds of electrical outlets there that can be found in most bathrooms -- the ones that shut down when there’s an overload or short circuit.

To keep your family safe, experts say you should inspect the electrical equipment at pools, docks, boats and marinas at least once a year. It’s also a good idea to get a shock alarm or other similar product to warn people when there’s electricity in the water, experts say.

The Electric Shock Drowning Prevention Association, a group that calls for better safety standards, has counted 25 of these electrocutions across the country in the past five years.

The Johnsons say local laws never required them to have the faulty electric line inspected. In their daughter’s name, they want that to change.

“There are probably a lot of drownings that happen that could be from this that people don't know,” Casey Johnson said.


Old Crows

Calypso 2014 View Profile
Yep! Saw that a couple days ago. How unfortunate. Now they really need to follow up and tell everyone the root cause .....

Vic thank you!!! :thumbup:

Your post about ESD & faulty wiring/grounding in RVs has made me get a couple testers and increase my vigelence regarding shock hazards.
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Aqua Puttana

Poly - Thread Finder
Some information.

OSHA said:
Current Level Probable Effect On Human Body

1 mA Perception level. Slight tingling sensation. Still dangerous under certain conditions.

5 mA Slight shock felt; not painful but disturbing. Average individual can let go. However, strong involuntary reactions to shocks in this range may lead to injuries.

6-16 mA Painful shock, begin to lose muscular control. Commonly referred to as the freezing current or let-go range.

17-99 mA Extreme pain, respiratory arrest, severe muscular contractions. Individual cannot let go of an electrified object. Death is possible.

100-2,000 mA Ventricular fibrillation (uneven, uncoordinated pumping of heart). Muscular contraction and nerve damage begin to occur. Death is likely.

2,000+ mA Cardiac arrest, internal organ damage, and severe burns. Death is probable.

Source: OSHA

This 30 amp power monitor unit is designed to trip with 8 - 10 mA fault current. It is not to the standard of a personal protection 5 mA trip level, but it will offer some protection and warning against Hot Skin where the vehicle metal becomes energized.

Surge Guard 30 Amp Portable Surge Protector with Ground Fault Protection
Catalog Item # 74402

Whenever we plug our van into shore power I use a 20 amp GFI unit right at the plug. For an A/C unit to run on 20 amps you need to be careful with selecting when to run other equipment. What I use is similar to this.

This is an inexpensive option. It may not fit into some weather cover protected receptacles. (The cord type unit above has more flexibility for that.) Combining the Tower unit with a short cord would give more flexibility.

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Aqua Puttana

Poly - Thread Finder
Thanks for the information. Sad news though.

Aqua, your original post was such good information that I never forgot it. And now this same preventable tragedy has reportedly happened again, which prompted me to think back to this thread.
Unfortunately as with this accident there are often multiple victims. The first person appears to be drowning so others go in to help only to find it wasn't just drowning. One in AZ didn't live. Let's hope the others recover properly.


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