Section 6: Lights and Sound Signals 75
Section 6: Lights and Sound Signals
N
avigation lights serve three purposes:
1. T o alert other boats of your presence and
relative location
2. T o tell other boats something about your
vessel’s size, speed, course, and type
(sail, power)
3. To enable you to properly apply the Navigation
Rules
If you operate your boat at night, learn
what the various lights signify, especially
those on tugs, barges, and large vessels.
That knowledge could save your life.
You are required to equip your boat
with the correct navigation lights and display
them when operating between sunset
and sunrise and during periods of reduced
visibility (see Table 6-1). Lights that satisfy
International Rules meet requirements of
the Inland Rules.
TYPES OF NAVIGATION
LIGHTS
There are five types of vessel navigational
lights, four of which are shown in Figure
6-1. Table 6-2 shows the distance that
lights must be visible. The distance varies
with the length of the boat.
Masthead Light is a white light
placed over the fore and aft centerline of
the vessel. The light is unbroken over a
225-degree arc of the horizon. The light
shows from dead ahead to 22.5 degrees
abaft the beam (behind the beam) on
either side of the vessel. Masthead lights
are used only when a vessel is under
power. Vessels less than 12 meters may
combine the masthead light with the stern
light so as to be visible for 360 degrees.
All-Around Lights are visible 360
degrees around the horizon. They may be
white, red, green, or yellow, depending on
their function.
Sidelights are a green light on the
starboard side and a red light on the port
side each showing an unbroken light over a
112.5-degree arc of the horizon and so fixed
as to show the light from dead ahead to
22.5 degrees abaft the beam on its respective
side. On a vessel of less than 20 meters
in length the sidelights may be combined in
one lantern (combination light) carried on
the fore and aft centerline of the vessel.
Stern Lights are white lights that shine
135 degrees aft (67.5 degrees from directly
astern and to each side of the vessel). When
you see a stern light of another vessel, you
will not see its sidelights or masthead light.
Towing Lights are yellow lights with
the same characteristics as stern lights.
They are mounted at the stern on towing
vessels. A towing vessel is a power-driven
vessel towing astern or alongside, or pushing
ahead.
Navigation Light
Requirements
Table 6-1 summarizes the light requirements
by type and size of boat. Figures 6-2
through 6-8 show the requirements visually.
Figure 6-1. Vessel navigational light
1
2
3
4
5
6
7
8
9
10
11
12
13
112.5°
SIDELIGHT
112.5°
SIDELIGHT
135°
STERN
LIGHT
360°
ALL-ROUND
WHITE
LIGHT
225°
MASTHEAD
LIGHT