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. 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.
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 various naval communication codes have been developed and widespread in the Marine across the world, such as the British 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. The flags were designed to be recognised even if partially covered.