52 s SOUTHERNBOATING.COM s MARCH 2016S
tudies indicate that the odds of
your boat being hit by lightning
are about 1,000 to 1. You
can increase those odds by two or
three in the southern states where
thunderstorms are more numerous.
That may still not sound like much
of a risk, yet the odds of a person
being struck by lightning are almost
a million to one in any given year—
and most people seek shelter when
a thunderstorm approaches. Even
a fairly benign-looking thunderhead
without much in the way of wind or rain
can produce lightning, and lightning
bolts can strike far from the parent
thunderstorm. “Positive giants,” bolts
from the top of a cumulonimbus cloud,
can travel miles from the storm base.
Lightning typically strikes the tallest
object, and boats on the water fi t that
description. As you would expect,
sailboats with high masts have the
greatest risk, but even PWCs have been
hit. A lightning bolt can easily damage
or destroy electronic equipment, and
the incredibly high voltages can evenblow holes through hulls. Fires are
certainly a strong possibility. Lightning
also poses great risks to those on
board, with injuries that range from
minor scrapes to permanent disabilities
and even death.
Can you keep your boat from being
hit by lightning? No. Can you protect
your boat and everything and everyone
on it from lightning? Yes! Lightning
protection for a boat is similar to that
for homes or buildings, and the original
concept is credited to Benjamin
Franklin. In 1749, Franklin formulated
the idea of a lightning rod as part of
his research on atmospheric electricity.He believed a large metal pole would
attract lightning strikes, and attached
wires could dissipate the electricity
harmlessly into the ground.
With modern lightning protection,
you’re not trying to attract lightning
bolts, just intercept them before they
do damage. The basic principle is still
the same as Franklin’s: Have the bolt
hit a “lightning rod,” now referred to
as “air terminals,” and then direct the
electrical charge via conducting wires
into, in this case, the water.
The most basic lightning protection
system (LPS) uses the mast as a
lightning rod/air terminal, the interceptor
of the lightning strike. A metal mast
will work, but for non-metal masts a
pointed metal spike or a prefabricated
air terminal can be mounted on the
mast top. This in turn is connected to
“down conductors,” cables or strips
using aluminum or copper, which will
take the electric charge down to a
ground plate. The plate should be at
least one square foot in area and be
made of a good conducting material.DO IT YOURSELF
Eluding Zeus’ Wrath
Protect your boat from lightning.
Siedarc sparking electrodes are installed
around the hull just above the waterline.MARINELIGHTNING.COM