Navigation Light Rules


Navigation Light Rules graphic comparing sailboats, boats at anchor and powerboats

By Tom Burden, Last updated: 4/30/2019

Recreational boats operating at night are required to display navigation lights between sunset and sunrise. Recent changes to the Inland Navigation Rules make them nearly identical to the International Rules, so we will describe the International Rules to simplify the choices.

Basic Rules and Definitions

  • Port sidelights are red, starboard sidelights are green and both shine from dead ahead to 112.5° aft on either side.
  • Stern lights are white and shine aft and 67.5° forward on each side. (Thus, the sidelights and stern light create a full circle of light.)
  • All-round lights are white and shine through 360°.
  • Masthead lights are white and shine from 112.5° on the port side through dead ahead to 112.5° on the starboard side for a total of 225° forward. They must be above the sidelights.
  • Sailboats under power are considered powerboats.
  • Sailboats with sails up during the day, but are also under power, must fly a black "steaming cone," with its point downward, where it can be seen. When under power they must follow the rules of the road for powerboats.

Chuck Hawley discusses options for navigation lights on your boat and what lights you can combine.

Navigation Lights Requirements Depend on Vessel Size

Navigation lights requirements vary depending on the length of the boat. Larger boats are required to use lights with a higher visibility range and cannot combine sidelights into a single bi-color light.

Powerboats and Sailboats When Under Power

The basic rule is that side lights, a masthead light and a stern light are required. Permissible variations to this rule appear below. NOTE: Sailboats operating under engine power are considered power-driven and must follow the “Under Power” rules.

  • Powerboats that are less than 12m (39.4') may substitute a single all-round light for separate stern and masthead lights.
  • Powerboats and sailboats under power that are less than 20m (65.7') can substitute a single bi-color light for sidelights.

Sailboats When Under Sail

The basic rule is that sidelights and a stern light are required. Permissible variations to this rule appear below.

  • Sailboats less than 20m (65.7') can substitute a tricolor light for separate sidelights and stern light—or a bi-color light and a stern light may be substituted.
  • Sailboats less than 7m (23') shall, if practicable, exhibit lights as explained above. An acceptable substitute is to keep ready at hand an electric torch or lighted lantern (flashlight) that shows a white light that shall be exhibited in sufficient time to prevent collision.
  • During the day, sailboats that are under power with their sails hoisted are required to display a motoring cone with its apex pointed down.

Oar-Driven and Paddled Vessels (Rowboats, Kayaks, Canoes)

  • Rowed or paddled vessels may exhibit the lights for a sailboat. An acceptable substitute is to keep ready at hand an electric torch or lighted lantern (flashlight) that shows a white light that shall be exhibited in sufficient time to prevent collision.

Vessels at Anchor

  • When anchored at night outside a designated anchorage, an all-round light visible for at least 2nm is required.
  • During the day, when anchored outside a designated anchorage, a black anchor ball must be displayed.

Minimum Visibility Range

  • Boats less than 12m (39.4'), sidelights must be visible for at least 1nm. All other lights must be visible for at least 2nm.
  • Boats less than 20m (65.7'), a masthead light must be visible for 3nm. All other lights must be visible for 2nm.
  • Boat over 20m (65.7') and less than 50m (164') must display a masthead light visible for 5nm. All other lights must be visible for 2nm.

Other Requirements—For Boats Greater Than 20m (65.7')

  • A copy of the Navigation Rules and Regulations must be kept on board at all times. See our selection of books.

Planning on Installing New Navigation Lights?

If your next weekend project is repairing broken navigation lights or upgrading to LEDs, watch this video first. Chuck Hawley points out some common mistakes boat owners make when installing navigation lights that will make your lights less visible and in some cases not compliant with USCG regulations.


Replacing Damaged Lights

Pole lights are often damaged if they are improperly used as a handle when getting in the boat. Chuck Hawley discusses some options for replacement with mounting options to fit any boat.


Portable Navigation Lights for Dinghies, Canoes and Kayaks

While smaller boats are allowed to use a flashlight or spotlight for collision avoidance, an inexpensive, portable bi-color light will keep you safer on the water. Chuck Hawley discusses some options.