Chapter 3: Operating Your Boat—Safely
Navigation Lights

Navigation lights help you and other boaters determine which is the give-way vessel when encountering each other at night. These lights must be displayed from sunset to sunrise and during periods of restricted visibility, such as fog. Chapter 4 has the legal requirements for your state. There are four common navigation lights.

Sidelights: These red and green lights are called sidelights (also called combination lights) because they are visible to another vessel approaching from the side or head-on. The red light indicates a vessel's port (left) side; the green indicates a vessel's starboard (right) side.
Sternlight: This white light is seen only from behind or nearly behind the vessel.
Masthead Light: This white light shines forward and to both sides and is required on all power-driven vessels. (On power-driven vessels less than 39.4 feet in length, the masthead light and sternlight may be combined into an all-round white light; power-driven vessels 39.4 feet in length or longer must have a separate masthead light.) A masthead light must be used by all vessels when under engine power. The absence of this light identifies a sailing vessel because sailboats under sail display only sidelights and a sternlight.
All-Round White Light: On power-driven vessels less than 39.4 feet in length, this light may be used to combine a masthead light and sternlight into a single white light that can be seen by other vessels from any direction. This light serves as an anchor light when sidelights are extinguished.

Precautions at Night

Make sure your navigation lights are working correctly, and carry extra bulbs.
Use an all-round white light whenever the vessel is at anchor.
Reduce speed and proceed with caution. Never be in a hurry.
Be especially alert for everything in front of you. Avoid traveling alone at night; extra eyes can help you navigate.
Stop if visibility is severely restricted, and use your sound signals to alert others in the area.

Typical Recreation Vessels' Navigation Lights

Descriptions of Types of Lights	Illustrations of Types of Lights
Navigation lights of a sailing vessel
Navigation lights of a sailboat under power
Navigation lights of a power-driven vessel with an all-round white light and combination sidelights placed on the bow
Navigation lights of a power-driven vessel with masthead light, sternlight, and separate sidelights
All-round white light indicating a vessel anchored away from the dock