Electric Shock Drowning – Are You At Risk From This Silent Killer?

Electric shock drowning, referred to as ESD, is a relatively new danger to swimmers and boat owners.  With so many more docks now connected to shore power for lights and other electrical conveniences, more people each year are falling victim to ESD.  And since most people are completely unaware of this risk, we will continue to read about additional innocent victims each year.

Electric Shock Drowning comes about when small amounts of 120 volt alternating current leak into fresh water in places where swimming occurs.  Swimmers can be electrocuted or incapacitated by this AC leaked current.   This is a fresh water phenomenon as fresh water is highly resistant to electrical flow, meaning that a swimmer caught in the flow of escaped electrical current now becomes the path of least resistance for this current trying to return to its source.   It takes very few amps to incapacitate a person and lead to drowning.  Salt water by contrast has a low resistance to electricity so that the current would flow around a swimmer in salt water.

Electric shock Drowning incidents are most common around docks and marinas, but there have also been cases reported at water fountains, irrigation ditches, golf course ponds and other bodies of water.  Many cases may simply be written up as drowning if no one was there to hear the victim cry out before he or she drowned.  Despite these other places for ESD, the most common cause comes from a boat plugged in to shore power that is leaking this current into the water around it.  Before AC current can escape into the water around the boat, two things must happen.  The first is that the boat itself must have some electrical fault on board.   This would be a short circuit of some type or another, a wiring error or a malfunctioning appliance which is sending AC electricity away from its intended path.  Remember that AC electricity travels in a loop, from its source to the load and back again, forming what is called a circuit.  When the circuit is broken, AC electricity will try to find a way back to its source.  Proper AC setup requires that there be a green grounding wire serving as a backup return path for the electricity to complete its circuit if there is a fault in the circuit.   So the second thing that must go wrong is that the grounding system is broken or fails so that the AC current cannot return to its source.

So what can you do to protect yourself and your loved ones from ESD?  The best plan would be to never swim around docks or marinas where shore sourced electricity is present unless that electricity is turned off.  This is also why rough play on docks is so dangerous as it could lead to someone falling into the water around the dock.  Now if you must swim or dive around your boat in order to work on fittings or equipment, you should be sure that all electricity is turned off before you enter the water.  Should you ever feel tingling or shocks while swimming, then you should not return to the dock.  Touching a metal ladder in this case could be immediately fatal.  Instead, swim away from the dock or marina and head to shore 100 yards or more away.  To rescue an ESD victim, do not go in the water as that could make you a victim as well.  Instead, turn off the shore power connection at the meter or unplug the shore power cords, then throw a line to the swimmer or row out to help the victim.  And now that you know more about ESD, please spread the word about these risks to all of your friends and family who have docks or spend time at marinas and might be at risk.

For those of you who own docks with shore power, there are a few additional precautions you should take.  Post no swimming signs at your dock.  Only hire trained marine electricians to install or service the wiring at your dock.  Those trained as land electricians do not have the training or understanding to safely install or service wiring in a marine environment.  You can also purchase testers that can test your dock and the waters around it for electricity leaks.  Please also consider the following protective devices for your dock.

Isolation Transformer – This device transfers electricity from the shore to the boat without the shore wires physically touching the boat’s wires.  If you have a fault, then the current no longer seeks a path through the water back to shore.

Galvanic Isolators – These are designed to help prevent your boat from suffering from or contributing to galvanic corrosion while plugged in to shore power.  Choose a failsafe model that requires that if it fails, it will fail in the off position.

Reverse Polarity Indicator – Can tell you if a neutral wire becomes hot thus removing your protections from circuit breakers that are installed on hot wires.

Growing up around water, I know I have many wonderful memories of swimming and playing around docks.  But we need to rethink this tradition as our docks are changing and becoming more dangerous places.  Please share this information with anyone you know who may be at risk.

At Clinard Insurance Group, located in Winston Salem, NC, we want all insurance buyers to be informed consumers.  If you need any help at all with your personal auto insurance, your home insurance or boat insurance or even your life insurance, please feel free to call us, toll free, at 877-687-7557 or visit us on the web at www.ClinardInsurance.com.