Blinker Lights:
Flashing Morse Code

The use of lights aboard ships began in the 16th century, when lanterns were placed on the sterns of Spanish and Dutch galleons sailing in large fleets. The lights kept the fleet together and prevented collisions. By the mid-19th century, red and green running lights and white bow lights were adopted to prevent collision.

The use of lights for spelling out messages in Morse code dates back to 1867. With the advent of electric lights in the 1890s, the "blinker light" became an effective tool for signaling. Most widely used by naval ships, blinker lights were essential for merchant ships sailing in wartime convoys and observing radio silence. Blinker has remained a useful backup for merchant vessels, and until the late 1980s deck officers were trained in its use. Usually however, blinker work was done by the Radio Officer.

Above: Blinker was used on World War II convoys to preserve radio silence. Photo courtesy U.S. Naval Institute.

A Navy signalman flashes blinker. U.S. Navy Photo.