Mariners
are particularly at risk
to the threat of
lightning. Marine vessels
are often the tallest
objects in a large open
space. Seeking the tallest
objects, lightning has
blown out the bottom of
boats and caused millions
of dollars in damage to
navigational equipment,
and electrocuted crew and
passengers.
How
do you know if you are in
danger?
Lightning
is a threat whenever:
·
You see
lightning or hear thunder
·
You hear
loud static on your AM
radio
·
You hear
buzzing sounds on radio
antennas
·
Mastheads
begin to glow
St. Elmo’s Fire
The glow on
the masthead produced by
an extreme buildup of
electrical charge is known
as St. Elmo’s Fire.
Unprotected mariners
should immediately move to
shelter when this occurs.
Lightning may strike the
mast within five minutes
after it begins to glow.
The
principal lightning safety
guide is the 30-30 rule.
The first “30” represents
30 seconds. If the time
between when you see the
flash and hear is 30
seconds or less, the
lightning is close enough
to hit you. If you haven’t
already, seek shelter
immediately.
The
second“30 stands for 30
minutes. After the last
flash of lightning, wait
30 minutes before leaving
your shelter. More than
one half of lightning
deaths occur after a
thunderstorm has passed.
How close
is the Lightning and is it
coming my way?
You can
tell how close you are to
a lightning strike by
counting the seconds
between seeing the flash
and hearing the thunder.
For every five seconds you
count, the lightning is
one mile away. If you see
a flash and instantly hear
the thunder, the lightning
strike is very close. Take
shelter immediately.
A hand
bearing compass can be
used to determine if you
are in the path of a
storm. By observing the
storm’s ground flashes and
using a series of
bearings, you can plot the
approach of a
thunderstorm. If the
bearing of the flashes
doesn’t change, the
average storm is heading
toward you. It is time to
alter your course.
What to do
when Lightning threatens?
Before
setting out to sea know
what conditions to expect.
Listen to a NOAA
Weather Radio for
weather information and
plan your trip
accordingly. If severe
weather is approaching or
forecasted, the best bet
is to stay ashore.
When
thunderstorms threaten,
mariners should stay away
from the water, get to
shore if already underway,
get out of their vessels
and seek shelter inside a
sturdy, closed building,
vehicle or below decks.
Even when
conditions look good,
mariners should still
leave a float plan with a
marina or someone ashore
and make sure they have an
escape route planned in
case a thunderstorm cuts
off the original course
back to land. Conditions
can change very quickly.
If a
thunderstorm catches you
while you are at sea,
follow these safety
guides:
·
Keep away
from metal objects not
grounded to the vessel’s
protection system. Contact
with them during a direct
hit can cause
electrocution.
·
Stay out of
the shower. The electrical
charge often travels along
and through plumbing.
·
Wear a life
jacket at all times. A
victim struck by lightning
can be rendered
unconscious and fall
overboard.
·
Stay tuned
to NOAA
Weather Radio
for the latest warnings,
watches, advisories And
forecasts from the local
National Weather Service
office.
Remember…
