Suspect you’re in danger?
Unfortunately, ESD is not a constant presence felt equally by all swimmers. People react differently to varying amounts of stray voltage, depending on body size and composition. So while you may feel fine, it could be affecting a nearby child or adult differently.
If you suspect you may be in danger of ESD, do not head towards the dock, as this could be the source of the voltages. Instead, shout out what is happening (you won’t be able to shout if you begin to drown) and back slowly away from the area. Instruct others to do the same, and inform everyone in the area of the situation once you’re out of the water.
Note: Stray electrical voltage is not always a constant presence in the water. The water may be fine for hours, but when the AC unit or onboard water heater flips on, the water can become instantly energized.
TOOL NOTES
Unfortunately, ESD is not a constant presence felt equally by all swimmers. People react differently to varying amounts of stray voltage, depending on body size and composition. So while you may feel fine, it could be affecting a nearby child or adult differently.
If you suspect you may be in danger of ESD, do not head towards the dock, as this could be the source of the voltages. Instead, shout out what is happening (you won’t be able to shout if you begin to drown) and back slowly away from the area. Instruct others to do the same, and inform everyone in the area of the situation once you’re out of the water.
Note: Stray electrical voltage is not always a constant presence in the water. The water may be fine for hours, but when the AC unit or onboard water heater flips on, the water can become instantly energized.
TOOL NOTES
- Instead of using cabin power, consider alternatives like solar panels to charge deep-cycle batteries for boats and lifts.
- Never use a standard extension cord to run power to your dock or boat. Use a UL-approved marine shore power cord with a built-in GFCI.
Electric shock drowning (ESD) results from stray voltage entering the water from AC sources. In freshwater, which is a poor conductor, the current radiates out from the boat or dock and uses a swimmer’s body as a ground. Amperages as low as 3 milliamps (mA) are enough to cause muscle paralysis and stop breathing.
Despite recent fatalities of several children in Missouri and Tennessee, ESD is not widely known. It’s most common around marinas, but with today’s cabin’s waterfronts becoming more energized, it’s essential that every cabin owner take the necessary precautions to prevent this deadly condition from developing near their dock and boat.
What causes ESD?
The stray current that causes ESD leaks out of electrical wires, connections or appliances. In a functioning, intact electrical system, this stray current would be returned to the earth via the electrical ground. However, if the ground wire is broken or compromised, that stray current seeks an alternate path. Typical AC sources include onboard marine AC units, water heaters, or even extension cords running along docks.
Without a functioning ground, stray voltage will travel to the metal parts of a dock, boat propellers, or other submerged metal. In freshwater, which has low conductance, the current then radiates outward, seeking a ground. The human body, which is saltier than freshwater, serves as a voltage conduit.
Prevent ESD in your dock area
The easiest and most foolproof way to avoid ESD is to not run AC power to your boat or dock, and avoid swimming near areas (like marinas) that have power run over the water.
If power over water is unavoidable, it is imperative that all electrical equipment on your boat or dock is in excellent working order. All electrical components on your boat or dock should be tested regularly by a certified electrician familiar with marine safety.
Despite recent fatalities of several children in Missouri and Tennessee, ESD is not widely known. It’s most common around marinas, but with today’s cabin’s waterfronts becoming more energized, it’s essential that every cabin owner take the necessary precautions to prevent this deadly condition from developing near their dock and boat.
What causes ESD?
The stray current that causes ESD leaks out of electrical wires, connections or appliances. In a functioning, intact electrical system, this stray current would be returned to the earth via the electrical ground. However, if the ground wire is broken or compromised, that stray current seeks an alternate path. Typical AC sources include onboard marine AC units, water heaters, or even extension cords running along docks.
Without a functioning ground, stray voltage will travel to the metal parts of a dock, boat propellers, or other submerged metal. In freshwater, which has low conductance, the current then radiates outward, seeking a ground. The human body, which is saltier than freshwater, serves as a voltage conduit.
Prevent ESD in your dock area
The easiest and most foolproof way to avoid ESD is to not run AC power to your boat or dock, and avoid swimming near areas (like marinas) that have power run over the water.
If power over water is unavoidable, it is imperative that all electrical equipment on your boat or dock is in excellent working order. All electrical components on your boat or dock should be tested regularly by a certified electrician familiar with marine safety.
GFCI = Standard equipment
Ground fault circuit interrupters (GFCIs) are a common fixture in bathrooms, laundry rooms and kitchens – anywhere electricity and water meet. GFCIs should also be standard equipment for any dock or boat power pedestal. GFCIs are meant to stop (or “interrupt”) the electrical current whenever it detects a 50–100 mA difference between what’s going out and what’s coming back to the ground. That difference in amperage is a
clear indication of stray voltage.
If your boat or dock power station has a GFCI (as it should) and it trips, do NOT simply reset the switch. Rather, bring a certified electrician in to determine the source of the problem. The 50 mA difference it is detecting could easily be going into the water, creating a deadly hazard for nearby swimmers.
Ground fault circuit interrupters (GFCIs) are a common fixture in bathrooms, laundry rooms and kitchens – anywhere electricity and water meet. GFCIs should also be standard equipment for any dock or boat power pedestal. GFCIs are meant to stop (or “interrupt”) the electrical current whenever it detects a 50–100 mA difference between what’s going out and what’s coming back to the ground. That difference in amperage is a
clear indication of stray voltage.
If your boat or dock power station has a GFCI (as it should) and it trips, do NOT simply reset the switch. Rather, bring a certified electrician in to determine the source of the problem. The 50 mA difference it is detecting could easily be going into the water, creating a deadly hazard for nearby swimmers.
Hubbell Electrical Systems 
None
None
Wilderness Wonders Rustic Cabin Wind ...
None
