What Do the Trilogy Flags Mean?

Captain Riley Coon, with TRILOGY flags.


One of the many questions guests ask our Crew is:

What do the flags represent?


It’s a very simple answer: The flags on the Trilogy logo each represent a letter, which when put together spell out "Trilogy." Nautical flags are an international code system used by ships at sea to communicate with one another or to people on shore. They can be used alone or in combination and are helpful in situations of language barriers or radio silence. The flags spell out short messages regarding safety of navigation. When the flags are used individually or in specific combination they have special meanings:

One-flag signals are urgent or very common signals.

Two-flag signals are mostly distress and maneuvering signals.

Three-flag signals are for points of the compass, relative bearings, standard times, verbs, punctuation, also general code and decode signals.

Four-flags are used for geographical signals, names of ships, bearings, etc.

Five-flag signals are those relating to time and position.

Six-flag signals are used when necessary to indicate north or south or east or west in latitude and longitude signals.

Seven-flags are for longitude signals containing more than one hundred degrees.

From Maritime Connector (2017).  International Maritime Signal Flags.  Available at http://maritime-connector.com/international-maritime-signal-flags/.  Accessed 13 January 2017.

Where did the flags come from?

Various flag systems were in use by the navy and private parties, however in 1855 the British Board of Trade drafted the first international code consisting of 18 flags. The system included universal and British only signals. During World War I, communications by flags failed more often than it succeeded and the system was revised to include seven languages. Many years and many modifications later, the system has become less about spelling out communications and more focused on relaying safety information.

What's with the primary colors?

Since not all colors are easily distinguishable at sea, International Code Flags are made up of black, white, red, blue and yellow. The colors that are combined are specifically chosen for simple discernment. 


All material is sourced from this document unless otherwise noted:

INTERNATIONAL CODE OF SIGNALS, For Visual, Sound and Radio Communications, United States Edition.