Tri Color Round Navigation Light
A tri-color round navigation light is a single, combined lantern that houses a red, a green, and a white light in one unit, typically mounted at the top of a sailboat's mast. This compact design is used by sailboats under 20 meters (65.6 feet) in length when they are under sail only, as specified by the International Regulations for Preventing Collisions at Sea (COLREGs).
Function and Visibility
The primary function of the tri-color light is to communicate the sailboat's presence, position, and direction to other vessels at night or in times of reduced visibility.
-
Red Light: Visible over an arc of 112.5 degrees on the vessel's port (left) side, from dead ahead to just behind the beam.
-
Green Light: Visible over an arc of 112.5 degrees on the vessel's starboard (right) side, from dead ahead to just behind the beam.
-
White Light: Functions as a sternlight, visible over an arc of 135 degrees from directly aft (behind) to 67.5 degrees on each side.
When combined in the tri-color light, these three arcs form a full 360-degree circle of light around the vessel.