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What are U.S. Navy Signal Flags?
Signal flags are a uniform set of easily identifiable nautical codes and are used to convey visual messages and signals between two ships or from ship-to-shore. They are based on a internationally recognized set of codes referred to as the International Code of Signals and is published in nine languages; English, French, Italian, German, Japanese, Spanish, Norwegian, Russian and Greek. The codes are important for safety and are crucial when language barriers exist.
The Origins of Signal Flag Codes
The use of flags to send messages while at sea actually dates back as far as the Middle Ages. However, the most detailed sets of flag codes were first developed by the British during the Napoleonic Wars (1799-1815) to convey messages and signals between two ships and ship-to-shore. The code of signals we use today was first established in 1857 by the British Board Trade and was revised in 1932. The International Code of Signals became effective in 1969 and this document is based on the 2003 revision in certain examples.
Pictures of U.S. Navy Signal Flags and What They Mean
Single-letter signals allocated to significations which are very urgent, important, or of very common use. Some flags have alternate meanings. Click the links or signal flag pictures to read more. The size of flags should vary based on the length of the vessel. The flag colors red, yellow, white, black, and blue are colors that tend to stand out the best at sea and are easily distinguished based on the contrasting colors inherent to the design. The flags are usually constructed using nylon fabric with double-stitched seams and are normally secured with nylon rope lines and rings. Note: examples of messages will be posted here once all the flags are described.
Pictures of Signal Flag Pennants
References:
1. USN, U.S. Navy Signal Flags, August 2009.
2. Lunde, P 2009, The Book of Codes
3. Bartlet, J., 2010
4. Flag Symbol Designs 2010 - HitGuru.net
5. http://en.wikipedia.org/wiki/International_maritime_signal_flags
6. National Geospatial-Intelligence Agency
7. Chapman Piloting, 63rd Edition 1999.
8. National Imagery and Mapping Agency, Pub 102, rev. 2003
U.S. Navy Signal Flags
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| The examples I through V provide two-letter signals for General Signal Code with variations and compliments. |
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| Two-Letter Signal Code Examples |
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| I. II. III. IV. V. |
Distress—Emergency Code Casualties—Damages Code Aids to Navigation—Navigation Code Maneuvers Code Miscellaneous Code |
Signal flags are a uniform set of easily identifiable nautical codes and are used to convey visual messages and signals between two ships or from ship-to-shore. They are based on a internationally recognized set of codes referred to as the International Code of Signals and is published in nine languages; English, French, Italian, German, Japanese, Spanish, Norwegian, Russian and Greek. The codes are important for safety and are crucial when language barriers exist.
The Origins of Signal Flag Codes
The use of flags to send messages while at sea actually dates back as far as the Middle Ages. However, the most detailed sets of flag codes were first developed by the British during the Napoleonic Wars (1799-1815) to convey messages and signals between two ships and ship-to-shore. The code of signals we use today was first established in 1857 by the British Board Trade and was revised in 1932. The International Code of Signals became effective in 1969 and this document is based on the 2003 revision in certain examples.
Pictures of U.S. Navy Signal Flags and What They Mean
Single-letter signals allocated to significations which are very urgent, important, or of very common use. Some flags have alternate meanings. Click the links or signal flag pictures to read more. The size of flags should vary based on the length of the vessel. The flag colors red, yellow, white, black, and blue are colors that tend to stand out the best at sea and are easily distinguished based on the contrasting colors inherent to the design. The flags are usually constructed using nylon fabric with double-stitched seams and are normally secured with nylon rope lines and rings. Note: examples of messages will be posted here once all the flags are described.
 A - ALPHA Diver Down |
 B - BRAVO Dangerous Cargo |
 C - CHARLIE Affirmative |
 D - DELTA Maneuvering Difficulty |
 E - ECHO Changing Course to Starboard |
 F - FOXTROT Disabled |
 G - GOLF Pilot Required |
 H - HOTEL Pilot Onboard |
 I - INDIA Changing Course Toward Port |
 J - JULIET On Fire |
 K - KILO Contact Me |
 L - LIMA Important Message |
 M - MIKE My Vessel Stopped, Lost Power |
 N - NOVEMBER Negative |
 O - OSCAR Man Overboard |
 P - PAPA Leaving Port |
 Q - QUEBEC Ship is Healthy |
 R - ROMEO Feel Your Way Past Me |
 S - SIERA Going Full Astern |
 T - TANGO Keep Clear, Am Trawling |
 U - UNIFORM You Are in Danger |
 V - VICTOR Need Assistance |
 W - WHISKEY Medical Aid Needed |
 X - X-RAY Stop! Watch for My Signals |
 Y - YANKEE Dragging Anchor |
 Z - ZULU Require Tug |
 0 - Zero Number Zero |
 1 - One Number One |
 2 - Two Number Two |
 3 - Three Number Three |
 4 - Four Number Four |
 5 - Five Number Five |
 6 - Six Number Six |
 7 - Seven Number Seven |
 8 - Eight Number Eight |
 9 - Nine Number Nine |
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Pictures of Signal Flag Pennants
References:
1. USN, U.S. Navy Signal Flags, August 2009.
2. Lunde, P 2009, The Book of Codes
3. Bartlet, J., 2010
4. Flag Symbol Designs 2010 - HitGuru.net
5. http://en.wikipedia.org/wiki/International_maritime_signal_flags
6. National Geospatial-Intelligence Agency
7. Chapman Piloting, 63rd Edition 1999.
8. National Imagery and Mapping Agency, Pub 102, rev. 2003