Although you may never see them displayed except at fleet
parades, around naval installations, and areas with heavy international shipping traffic, International code flags are used
to signal between two ships or between ship and shore. Also called signaling flags, they are a set of flags of different colors,
shapes and markings which used singly or in combination have different meanings. The flags include 26 square flags which depict
the letters of the alphabet, ten numeral pendants, one answering pendant, and three substituters or repeaters.
Only a few colors can be readily distinguished at sea.
These are: red, blue, yellow, black, and white; and these cannot be mixed indiscriminately. You will notice, for clarity,
the flags shown are either red and white, yellow and blue, blue and white, or black and white; besides plain red, white, and
One-flag signals are urgent or very common signals (see
meanings below). 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.
Some Useful Two Letter Signals:
|AC - I am abandoning my vessel.
||LO - I am not in my correct position: used by a light vessel.
||RU - Keep clear of me; I am maneuvering with difficulty.|
|AN - I need a doctor.
||NC - I am in distress and require immediate assistance.
||SO - You should stop your vessel instantly.|
|BR - I require a helicopter.
||PD - Your navigation lights are not visible.
||UM - the Harbour is closed to traffic.|
|CD - I require immediate assistance.
||PP - Keep well clear of me.
||UP - Permission to enter Harbour is urgently requested. I have an emergency.|
|DV - I am drifting.
||QD - I am going ahead.
||YU - I am going to communicate with your station by means of the International code
|EF - SOS/MAYDAY has been canceled.
||QT - I am going astern.
||ZD1 - Please report me to the Coast Guard, New York|
|FA - Will you give me my position?
||QQ - I require health clearance.
||ZD2 - Please report me to Lloyds, London.|
|GW - Man overboard. Please take action to pick him up.
||QU - Anchoring is prohibited.
||ZL - Your signal has been received but not understood.|
|JL - You are running the risk of going aground.
||QX - I request permission