70 Chapter Two
(continued from page 69)
Inland (State) Waters
Obstruction Marks
State water obstruction mark is a black/
white vertically striped buoy.
It may show a white reflector or
quick flashing white light.
NUMBERS AND LETTERS
ON AIDS TO NAVIGATION
Most navigation aids carry numbers or letters
according to their position and use;
this helps with their visual identification
(Figure 5-14).
Lateral aids (red or green) are numbered
for identification of a specific aid.
• Green aids are odd-numbered, usually starting
with “1” when entering from seaward,
and numbers increasing as you go inland.
• Red are even-numbered, usually starting
with “2” when entering from seaward,
and numbers increasing as you go inland.
Most other aids are lettered, one or more
characters, capitalized.
Aids are labeled on a chart to indicate
their number or name within quotes (“ ”);
not all numbers in sequence may be present.
LIGHTED MARKS
Any aid may be lighted for better visibility
at night.
Buoys
Generally, lighted buoys will be tower
structures, thereby losing their identity as
nuns or cans. No “N” or “C” is labeled on
the chart (Figure 5-15).
Some newer lighted buoys retain the
nun/can shape.
The charted symbol for a lighted buoy
adds a magenta disc (circle) behind and
centered on the black circle.
Beacons
• Lighted beacons can be lighthouses,
tower structures, or poles.
• They can be on land or on the water
affixed to the bottom.
• They may also show a daybeacon board
(green or green/red square; or red or red/
green triangle)
The chart symbol for a beacon is a magenta
flare with a solid black circle marking the
location (resembling an exclamation point)
(Figure 5-16).
Figure 5-14. Numbers and
letters on aids
Figure 5-15. Tower buoys
Figure 5-16. Chart symbols for lighted navigation
aids
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lighted beacon
lighted buoy