In order to enjoy your time on the water, first and foremost you need to know that you and your passengers are safe. In addition to the usual safety procedures for boating, that means having the appropriate marine lights on your boat. The laws and regulations around boat navigation lights are detailed by the US Coast Guard and are designed to keep everyone on the water as safe as possible. Boat navigation lights are required between sunset and sunrise, and at all times of reduced visibility. Marine lights indicate the size of vessel, its activity, and direction of travel. Properly used boat navigation lights ensure that all vessels on the water can understand each other. General Rules for Marine Boat Navigation Lights On all vessels, boat navigation lights will have a specific color, location, range of visibility, and arc of illumination as required by marine light laws and regulations. The basic rules for boats under 65.6 feet are as follows: All around lights. As the name implies, all around lights project a full circle of light. They are white and provide 360º of white light. They need to be visible for 2 miles. Masthead lights. These are also white. They shine from 112.5º on the port side of the vessel 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. For boats less than 39.4 feet, visibility range is 2 miles; for those over 39.4 feet, it is 3 miles. Sidelights. Sidelights are red and green, and the color matters. 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. Stern lights. These are white lights that shine aft 135º (67.5º on each side). The visible range of illumination should be 2 miles. Navigation Light Rules for Powerboats 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. Navigation Light Rules for Sailboats 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. It’s the Operator’s Responsibility to Understand Boating Light Requirements As a responsible vessel operator, it is vital that you know how to interpret the lights that you see, as well as display the boat navigation lights you are required to have. The marine lights are the sole responsibility of the owner/operator, not the manufacturer, importer, or dealer. Some boats come with lights that do not meet legal requirements. It’s also important to remember that the angles of visibility must be met when the boat is underway, and you may need to adjust your lights accordingly.