Boat Navigation Lights: What Each Color Represents

Understanding boat navigation lights is a basic safety requirement when you take to the water in your vessel. As a boat owner, it’s up to you to have the correct lights installed on your boat and have them colored and calibrated in the correct way. When all boat owners use their lights properly and understand the lights of other boats that they see, the safety of everyone on the water is protected.

White Lights

White lights give you an overview of the vessel since they are either all around, mast or stern.
*All around lights. As the name implies, all around lights project a full 360º circle of light. They would be projected from the center of the boat and need to be visible for 2 miles.
*Masthead lights. They shine from 112.5º on the port side of the boat through dead ahead to 112.5º on the starboard side. Therefore, the arc of illumination is 225º. Masthead lights must always be located above side lights (which are colored). For boats less than 39.4 feet, visibility range is 2 miles; for those over 39.4 feet, it is 3 miles.
*Stern lights. These lights shine aft 135º (67.5º on each side). The visible range of illumination should be 2 miles.


Colored lights are always sidelights and the different color indicates the side. Red lights are located portside, and green are starboard. The lights shine from dead ahead to 112.5º aft on either side of the vessel. On some boats, sidelights can be combined into one bicolor light. For boats less than 39.4 feet, the visible range should be 1 mile; for those over 39.4 feet, it is 2 miles.


For sailboats that are less than 7 meters long, the general boat navigation lights apply. If, however, regular marine lights cannot be used or installed practically, there is another option. Your sailboat must have an electric torch or lantern that emits a highly visible white light that you can deploy in time to prevent collisions.


Powerboats need to have a masthead light forward, sidelights and a stern light. Vessels less than 12 meters in length can have an all around white light and sidelights. Powerboats on the Great Lakes may carry an all around white light instead of a second masthead light and stern light combination. Sidelights may be combined into a single bicolor light fixed at the centerline of the boat.

Boat navigation lights are required between sunset and sunrise, and at any other times of reduced visibility. These lights can indicate the size of the boat, what it’s doing, and what direction it’s going. Boat lights are an essential way for vessels to communicate with one another.