Lights communicate the type and size of the boat, as well as its position and heading. There are many different light configurations for specific types of commercial boats, but in general, larger (and therefore more dangerous) vessels have more lights than smaller ones. It’s more important to be sure that you’re displaying the proper lights than to memorize all the possible light configurations for other boats. For a complete list of all possible light configurations, see the USCG Navigation Rules found at:
https://www.navcen.uscg.gov/?pageName=NavRulesAmalgamated
Boat lights are described based on their position on the boat and the field of view that they shine into. Notice how the side lights always conform to the stand on and give way zones. The masthead light can be an all around light, but frequently only covers 225° facing forward, particularly when it is coupled with a stern light.
Types of Boat Lights
Lights are required to be displayed from sunset to sunrise and during periods of restricted visibility, such as fog. The light configurations for sailboats are shown in the appendix. Most recreational boats will be covered by these few simple categories.
Position and heading are communicated by the light colors, as discussed in the section on stand on and give way zones. You can also judge the relative speed of a boat based on how its position changes with respect to your own.
Sailboat Lights
