We Value Your Privacy

We and our partners use technology such as cookies on our site to personalise content and ads, provide social media features, and analyse our traffic. Click below to consent to the use of this technology across the web. You can change your mind and change your consent choices at anytime by returning to this site.

Update Consent
Loading ...

Explanation for the Red & White Lights on Lighthouses

Updated November 21, 2016

Lighthouses are tall towers with lights at the top that sit on the edge of large bodies of water. Lighthouses inform ships of the location of land during bad weather conditions and if it is safe to approach land. Many lighthouse are still fully functional. Historically, they used small flames with reflected glass for light, but most have changed to electric light in different colours. Lighthouses use different light colours for several reasons.

Loading ...


The most common reason for a lighthouse to have flashing red and white lights is to distinguish it from other lighthouses. The specific pattern of red and white light, as well as the time interval between the flashes, is called the lighthouse's characteristic. In areas with treacherous waters, where there are multiple lighthouses, the characteristic of each lighthouse will inform the ship of its exact location. Some lighthouses only flash white, some flash red and some alternate between the two.


In areas with narrow bays or ports, lighthouses use red and green lights to distinguish the side of the entrance. In navigation, red lights are associates with the port side, or left side, and green is associated with the right. Upon entering a port, the ship will see the red light on the left.


Occasionally, lighthouses will use red light to notify incoming ships of danger. They will use a flashing red light or switch between red and white to distinguish the warning from their normal characteristics. Red traditionally means stop, and informs the ship to seek out further information.


In areas where the port is surrounded by many buildings, lighthouses use coloured light to distinguish themselves from the surrounding white lights. At night, it is difficult to differentiate between multiple white lights, so lighthouses use their characteristics for easier navigation.

Loading ...

About the Author

Loading ...