Non-Lateral Marks Having Regional or Infrequent Application
Isolated Danger Marks
Isolated danger marks are placed on, above, or near a
danger that has navigable water all around it. Figure
5-12 show how to identify isolated danger marks.
Approach them cautiously!
Special Marks
Used to mark features unique to location, purpose is
printed on chart (Table 5-6 and Figure 5-13).
1. Color is yellow, shape appropriate to location.
2. Symbol (unlighted) is a hollow diamond with a
black circle marking its location
3. Aids on the Intracoastal Waterway (ICW) have
yellow triangles or squares on lateral buoys,
which may otherwise be red or green, or a yellow
square for aids with no lateral significance.
Intracoastal Waterway (ICW) Marks
Yellow triangles indicate aids should be passed by
keeping them on the starboard (right) side of the vessel.
Section 5: Navigation Aids 69
Yellow squares indicate aids should be passed
by keeping them on the port (left) side of the vessel. A
yellow horizontal band provides no lateral information,
but simply identifies the aid to navigation as
marking the ICW.
Note: When following the ICW from New Jersey
through Texas, keep yellow triangles on your starboard,
yellow squares on your port, regardless of
the color navigation aid they appear on. Examples:
62
63
64
65
66
67
68
Table 5-5. Isolated Danger Marks
Color Black & Red Horizontally
banded. Top band
is black
Shape Skeleton tower
Topmark/Daymark Two black spheres
Light (if fitted) Color White Flashing,
Rhythm groups of 2
Identification Letters
Table 5-6. Special Marks
Color Yellow
Shapes
Unlighted Conical (nun) or Cylindrical
(can)
Lighted Skeleton tower
Daymark Yellow diamond
Light (if fitted)
Color Yellow
Rhythm Fixed or flashing
Identification Letters
Figure 5-12. Isolated danger marks Figure 5-13. Special marks