Color Coded Communication
Understanding symbols

Before having the class make sets of international alphabet flags, explain that when Captain Hull first spotted sails on the horizon off the coast of New Jersey, he raised the code signal for the day to find out if they were friend or foe. When the ships did not respond, Hull knew they were enemy vessels. Every nation had its own signal flags. For every day of the year, the U.S. Navy specified a different combination of flags to identify a ship as American. Today, there is an international set of flags that can be used on the seas or in harbor to help ships communicate with one another.

Ask students to color the flags according to the labels and create short messages by sequencing the flags, duplicating letters if necessary. Allow them to use the conventions explained in Scuttlebutt III whereby certain flags mean whole words or phrases. For example “blue peter,” the ‘P’ flag, is hoisted to indicate that a ship is about to leave harbor. You might also divide the class into teams to compete to see which team can decode another’s message the fastest.

Students might want to know how ships identified one another after sunset. Sailors hung lanterns on board in different configurations.

Have on Hand- red, yellow and blue crayons or colored pencils; tape, scissors and photocopies of signal flags.

Blank Worksheets:
Alphabet Flags

Part I (pdf)
Part II (pdf)
Part III (pdf)

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