12 December 2001
Secondary Lights. These lights, which also may be attended or
automatic, are established at harbor entrances and other locations where
the needs for high candlepower and long range are less necessary, and
on large inland waterways as intermediate aids in harbor channels and in
other inshore channels where the requirements of navigation indicate that
the range and candlepower of this class are necessary.
Range Lights. These are pairs of lights located to form a range in line
with the center of a channel or entrance to a harbor. The rear light is
higher than the front light and a considerable distance in back of it. The
length of the range and width of the channel govern the height and
distance of separation necessary between the lights. Range-light
structures shall be equipped with daymarks for ordinary daytime use.
Ranges may be used either ahead or over the stern.
Directional Lights. A directional light is a single light which will project a
beam of high intensity, separate color, or other special characteristic, in a
given direction. It has limited use in those cases where a two-light range
may not be practicable or necessary, and for other special applications.
The directional light is essentially a narrow-sector light with or without
adjacent sectors which give information as to the direction of and relative
displacement from the narrow sector.
Minor Lights. These are lights of relatively low candlepower usually
established in harbors, along channels, along rivers, and in isolated
locations. They are generally unattended and unwatched and should
operate automatically. Depending upon circumstances, these lights may
be displayed from towers, skeleton structures, or from a group of piles.
They shall be colored to distinguish them from the surrounding
background and from adjacent structures.
Lighted Buoys. These are floating aids showing from the upper of their
structures an automatically operated, low-candlepower light. Colors and
characteristics vary. Lighted buoys are established for the purpose of
definitely identifying spots. These include the entrance and side limits of
natural and dredged channels, centers of fairways, obstructions and
wrecks, isolated natural dangers in offshore or restricted waters, and for
special purposes such as quarantine or general anchorages. These lights
are powered by batteries.
Unlighted Buoys. These are floating aids of varying size, shape, and
color. They serve the same general purposes as lighted buoys. They are