Non-Lateral Aids to Navigation
Dayboards — May Be
|Range Dayboards — May Be Lettered
|Ranges are a PAIR of
aids to navigation. When the dayboards and/or lights appear to be in
line with each other (Figure "A"), it assists the vessel operator in
maintaining a safe course within the navigable channel. The
appropriate nautical chart must be consulted when using ranges to
determine whether the range marks the centerline of the navigable
channel and also what section of the range may be safety traversed.
Ranges are generally, but not always, lighted, and display
rectangular dayboards of various colors. Ranges which are lit 24
hours a day may not have dayboards.
|Typical Information and
|When lighted, may display any
rhythm except quick flashing
and flashing (2)
|NW White Light Only
|Information and Regulatory Marks
are used to alert
vessel operators to various warnings or regulatory
|Explanation may be placed outside the
crossed diamond shape, such as dam, rapids, swim area, ect..
||The nature of danger may be
indicated inside the diamond shape, such as rock, wreck, shoal,
||Type of control is indicated
in the circle, such as slow, no wake, anchoring, ect.
|For displaying information such as
directions, distances, locations, ect.
||Buoy used to
display regulatory markers
||May show white
may be lettered
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