How to Use Signal Flags

Signal flags have been used for centuries to communicate messages across long distances when other contact might be impossible. Most commonly used to communicate between ships, or indicate water and weather conditions, a set of signal flags consists of a flag for each letter of the alphabet, the number 0 through 9, and other short message flags.

Instructions

    • 1

      Learn to recognize the various signal flags. There are several different flag codes depending on your location in the world and the ship using the flags, the most common being the International Code of Signals and the U.S. Navy Flag Code.

    • 2

      Hoist flags in order to spell out the word or abbreviation you would like to signal. Each flag indicates one letter, number, or abbreviation for common signals.

    • 3

      Use one of the four repeater (or substitute) flags to duplicate letters when using only one set of flags. An example would be the common "SOS." This would be flagged using the flags for "S," "O," and the "1R," or First Repeater flag. This indicated the first letter in the string is to be repeated at this point. Repeater flags can be combined to spell more complicated five-letter words.

    • 4

      Use additional naval flags alone or in chain with other flags to indicate certain commands or conditions. Examples being the "EM" flag for "Emergency" and "NE" for "Negative."