For almost 2 centuries the International Maritime Signal Flag System has been used by mariners to send messages between two ships or ship and shore and are still in use today. Strung end to end and hung bow to stern from the rigging they are primarily used to dress vessels for ceremonials and other festive occasions. Also referred to as signaling flags, they are a set of flags of different colors, shapes and markings which used singly or in combination have different meanings. Signal flags consist of a set of 26 different square flags each representing a particular letter of the alphabet plus 10 pendants representing the numbers 0 to 9. With these 36 nautical signal flags, any message can be spelled out for all to see. In addition there is one answering pennant and three substituters or repeaters.

Nautical Flags - Alphabet & Numbers & Meanings with Morse Code

Nautical Flags - Weather Warning Flag Signals

Nautical Flags - 2 Flag Signals