[Code of Federal Regulations]
[Title 33, Volume 1]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 33CFR62.45]

[Page 148-149]
 
                TITLE 33--NAVIGATION AND NAVIGABLE WATERS
 
         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY
 
PART 62--UNITED STATES AIDS TO NAVIGATION SYSTEM--Table of Contents
 
              Subpart B--The U.S. Aids to Navigation System
 
Sec. 62.45  Light characteristics.

    (a) Lights on aids to navigation are differentiated by color and 
rhythm. Lighthouses and range lights may display distinctive light 
characteristics to facilitate recognition. No special significance 
should be attached to the color or rhythm of such lights. Other lighted 
aids to navigation employ light characteristics to convey additional 
information.
    (b) When proceeding in the Conventional Direction of Buoyage, aids 
to navigation, if lighted, display light characteristics as follows:
    (1) Green lights mark port (left) sides of channels and locations of 
wrecks or obstructions which are to be passed by keeping these lights on 
the port (left) hand of a vessel. Green lights are also used on 
Preferred Channel Marks where the topmost band is green.
    (2) Red lights mark starboard (right) sides of channels and 
locations of wrecks or obstructions which are to be passed by keeping 
these lights on the starboard (right) hand of a vessel. Red lights are 
also used on Preferred Channel Marks where the topmost band is red.
    (3) Certain lights marking the Intracoastal Waterway may display 
reversed lateral significance. See Sec. 62.49.
    (c) Yellow lights have no lateral significance. Except on the 
Western Rivers, see Sec. 62.51, white lights have no lateral 
significance. The purpose of aids exhibiting white or yellow lights may 
be determined by their shape, color, letters or numbers, and the light 
rhythm employed.
    (d) Light rhythms, except as noted in Sec. 62.51 for the Western 
Rivers, are employed as follows:
    (1) Aids with lateral significance display regularly flashing or 
regularly occulting light rhythms. Ordinarily, flashing lights 
(frequency not exceeding 30 flashes per minute) will be used.
    (2) Preferred Channel Marks display a composite group flashing light 
rhythm (groups of two flashes followed by one flash).
    (3) Safe Water Marks display a white Morse Code ``A'' rhythm (short-
long flash).
    (4) Isolated Danger Marks display a white group flashing two.
    (5) Special Marks display yellow lights with fixed or slow flashing 
rhythm preferred.
    (6) Mooring Buoys and Information and Regulatory Marks display white 
lights of various rhythms.
    (7) For situations where lights require a distinct cautionary 
significance, as at sharp turns, sudden channel constrictions, wrecks, 
or obstructions, a quick flashing light rhythm (60 flashes per minute) 
may be used.
    (e) Occasionally lights use sectors to mark shoals or warn mariners 
of other dangers. Lights so equipped show one color from most directions 
and a different color or colors over definite arcs of the horizon as 
indicated on the appropriate nautical chart. These sectors provide 
approximate bearing information since the observer should note a change 
of color as the boundary between the sectors is crossed. As sector 
bearings are not precise, they should be considered a warning only and 
not used to determine exact bearing to the light.
    (f) Aids to navigation may be fitted with light-reflecting material 
to increase their visibility in darkness. Green or red reflective 
material is used only on marks which, if lighted, would exhibit a light 
of that color. Yellow reflective material is used on special

[[Page 149]]

marks and on Intracoastal Waterway marks. No significance is attached to 
white reflective material.

[CGD 86-031, 52 FR 42640, Nov. 6, 1987, as amended by CGD 88-018, 54 FR 
48608, Nov. 24, 1989; CGD 97-018, 63 FR 33573, June 19, 1998]