thus, the principal purpose of a light structure is to
increase the height of a light above sea level.
Remember that a light placed at a great
elevation is more frequently obscured by
clouds, mist, and fog than one near sea level.
A lighthouse may also contain fog signaling and
radio beacon equipment. In lighthouses still staffed by
keepers, the lighthouse may also contain their
quarters, or the operating personnel may be housed in
separate buildings grouped around the tower. Such a
group of buildings is called a light station. Many lights
formerly operated by keepers are now automatic.
Secondary, minor, and automatic lights are located
in structures of various types. Those structures range
from towers that resemble those of important seacoast
lighthouses to such objects as a small cluster of piles
supporting a battery box and lens.
Solid colors, bands, stripes, and other patterns are
applied to lighthouses and light structures to make
them easier to identify. Lighthouses and light
structures may also be painted in contrasting colors
and various patterns to their background. (See fig.
9-9.) Minor structures sometimes are painted red or
black, like channel buoys, to indicate the side of the
channel on which they are located.
A lightship is a floating lighthouse located where
conditions make it impossible or impractical to build
a permanent structure.
Lightships in U.S. waters are painted red on the
hull, with the name of the station in large white letters
on either side. Other parts of the lightship that are
painted include the following: superstructure is
white; mast, ventilators, lantern galleries, and stacks
The lights, fog signals, and radio beacon signals
on lightships are given various characteristics for
purposes of identification. Like lighthouses,
lightships are described briefly on the charts and in
detail in Light Lists.
A lightship under way or off station hoists the
international code signal LO. This indicates that the
lightship is not in the correct position. The lightship
Figure 9-9.Various patterns of typical lighthouses.
must then observe the requirements of the Rules of the
Road for a vessel of that class.
At night when anchored on station, a lightship
shows only its beacon light and a less brilliant light on
the forestay to indicate the heading.
When a regular lightship goes in for overhaul or
repairs, the lightship's place is taken by a relief
lightship whose lights and signals have, as nearly as
possible, the same characteristics as the ship she
replaces. Relief lightships are distinguished by the
word RELIEF painted in white on either side.
Sectors of red glass are placed in the lanterns of
certain lighthouses to indicate danger bearings, within
which a ship will be in danger of running onto rocks,
shoals, or some other hazard. The arcs over which the
red light shows are the danger sectors whose bearings
appear on the chart. Although the light is red within
the danger bearings, its other characteristics remain