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Nautical Signals

The C.I.S. consists of 26 alphabetical flags, 10 numeric, three substitute and a code or recognition pennant. Learn here a little about its history and its meanings.

The International Code of Signals or Flag Code uses a clear and easily understandable “language”, and is of fundamental importance for the safety of everyone who goes to the sea.

Until the 16th century the signaling between ships was done by hoisting the sails in certain positions or firing guns. Therefore, we know that Vasco da Gama signalled as follows: A fire signal was an order to continue, two was to turn, three to hoist the sail and four to shorten sail.

On the other side, during the 16th and 17th centuries the English and Dutch raised a red flag to signal the beginning of a battle and a black to signal its end.

Since the beginning of the 18th century several naval communication codes have been elaborated and widely disseminated in the World Navy, such as that of the English Admiral Richard Howe in 1777. Other codes were also published such as the Danish (Rhode), the American (Rodgers) and the French (Reynold).

The review in 1961 resulted in the current code, which had been designed in 1855 and published in England in 1857, having been published for the last time in 1988 by the IMO (International Maritime Organization).

The C.I.S. consists of 26 alphabetical flags, 10 numeric, three substitute and a code or recognition pennant. All alphabetical flags, except the letter “R” have a different meaning. They can be combined with each other and read from top to bottom. In this way, flags are recognized even when they are partially covered.

International Code of Signals

FlagPhonetic spelling and CW alphabetMeaning
AlfaI have a diver in the water. Keep clear and navigate at low speed.
BravoI am loading or unloading, or transporting dangerous cargo.
CharlieYes (affirmative or the meaning of the former group should be interpreted as affirmative).
DeltaKeep away from me; I am manoeuvring with difficulty.
EchoI am turning towards starboard.
FoxtrotSuffering a breakdown; communicate with me.

Learn more about: Nautical terms and Sailors’ knots.

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