International maritime signal flags
International maritime signal flags or International
Code flags allow to send signals or entire messages
to communicate with other boats in sight.
This system, with nautical flags or maritime flags, serves to illustrate very clearly the situation of the vessel using it as a warning and consists of nautical flags (or maritime flags) that represent individual letters and numbers. Nautical flags and maritime flags are hoisted on the ship vertically in groups of four and are read from top to bottom.
In the sailing events, however, banners or maritime nautical flags take on other meanings. Also the NATO uses nautical flags to communicate even if the meaning of each flag is different from the International Code flags.