A ship cannot suspend operations merely because darkness falls and
daytime aids cannot be distinguished. For that reason, aids to navigation
are lighted whenever it is necessary and practical. For purposes of
identification, lights have individual characteristics regarding color,
brilliancy, and system of operation.
A lights characteristics are usually printed on the chart near its symbol.
Detailed information on any particular aid to navigation may be found in
the appropriate volume of the Light List.
As you learned in the previous chapter, the Defense Mapping Agency
Hydrographic/ Topographic Center (DMAHTC) publishes List of Lights
in seven volumes which cover aids to navigation outside the continental
Aids located in the United States and its possessions are described in
Light List volumes published by the U.S. Coast Guard.
Figure 4-1. Light List.