16 seamanship secrets
A light that fl ashes every 4 seconds has a period of 4 seconds.
A quick-fl ashing light has a period of 1 second. Other aids use special
patterns. A midchannel lighted buoy shows a distinctive Morse code letter
A (a dot and a dash—i.e., a brief fl ash followed by a longer one). You would
not need to time such an aid because its character reveals how it is used. Th at
is why you never see a midchannel buoy with a period noted next to its light
characteristic.- What is the light color, if any? Look at the sample buoy description above.
Th e color that immediately follows the characteristic is the light color. For
instance, Fl. G. 4s shows a green light. If you have a light characteristic
without a color indicated, it shows a white light. For example, Fl 4s
indicates a white light. Red or green lights are used only on aids that tell
you the safe side of passage (though not all lateral navaids are lighted).
Th ese lights, when present, will be the same color as the navaid itself.
On red-and-green or green-and-red preferred-channel aids, the light,
when present, always matches the color of the top band. Yellow aids carry
only yellow lights. Lighted special-purpose aids—such as red-and-white
midchannel buoys—carry white lights with unique fl ashing patterns (see
number 3 above).
These abbreviations are used to indicate light color:
R = red
G = green
Y = yellow
W (or no color indicated) = white- What is the sound, if any? Aids marking dangerous shoals and those located
in geographic areas where fog prevails oft en carry a bell, gong, whistle,
or horn signal. Note in the example that sound, if indeed the ATON has it,
comes last in the description. Th ere’s a lot of comfort in hearing the clang
of a bell buoy or the raspy sound of a gong buoy in a pea soup fog. And
there’s a lot to be said for laying a course to a buoy that you don’t have to
pinpoint in order to locate—especially a midchannel buoy surrounded by
deep water. If you don’t fi nd the buoy where and when you expected to,
shut down the engine or engines and listen. Ah, there it is, about a hundred
yards to starboard. Bells, gongs, and whistles operate by wave or swell action.
Clappers strike bell domes or gong disks to activate the sound. Th e up-and-
down action of swells causes whistles to produce their unique “sighing” tone
by compressing air through a diaphragm. Th e horn stands alone as the only
electronic signal. It’s usually reserved for large lighthouses located along
fog-shrouded coasts.