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.
