What do the marine warning flags mean?

Answer 1

Nautical flags are used by ships to communicate between each other or to send messages to the shore. Developing a system of flags acceptable, easy to understand and apply by all countries around the world was not an easy task and took time and effort, but at the end it is a fact and it is all worth. Nowadays, almost all countries recognize and follow the International Code of Signals (ICS) as a primary way of communication using color flags. The main purpose of the flags has remained intact over the centuries. Flags main application is to help ensure safety - both for the vessel and crew displaying the flag(s) and for the observers of the communicated message(s) - either other vessels or people on the shore.

Overall flags fall into four major groups - a single flag can denote a letter, a number, a specific message, or can indicate a repetition of a flag already displayed (these flags help eliminate the need of having multiple duplicates of the same flag on board). Flags can be used individually - for example, the letter flags can be used to spell out a word. However, letter flags also have a general message implied when used on its own. In addition, certain two or three flag combinations spell out more detailed messages as described by the International Code of Signals (last official edition was published in 1969 and the last revision is from 2003).