The "secrets" of the international nautical code

Have you ever heard of the International Nautical Code? Surely, if you are passionate about boats and navigation, if you already sail or if you would like to try it soon, you know very well what we are talking about.

However, if you have any doubts, that's what we're here for: here's an overview that will give you some of the right notions and some extra awareness!

The first thing you should know is that the International Nautical Code is part of the International Code of Signals and is used for communication between ships. It consists of a series of flags representing letters of the alphabet and numbers.

Let's try to decipher some signals....

To initiate good communication, flags should be displayed vertically in groups of four and well spaced apart. Reading is done from top to bottom. Each flag is assigned a specific meaning.

Let's take an example: the flag corresponding to the letter "A," when hoisted individually, is used to warn that one or more divers are in the vicinity of the ship and, consequently, that it is necessary to reduce speed and pay special attention. Another example? The flag indicating the letter "F" is used to signify that the ship is in trouble and direct communication is needed.

In the International Nautical Code, certain alphabetical flags can take on different meanings depending on the location of the ship. To be understood, the one representing the letter "L," if hoisted in port communicates that the ship is in quarantine, but if it is hoisted at sea while underway it means to communicate to those receiving the message that it is necessary to stop one's ship.

The letter "P" also has a double meaning: in port it indicates that the ship is about to set sail and that everyone should return to the ship, while in the open sea it signals that fishing nets are caught in an obstacle.

Other features of the international nautical code

Be aware that alphabetical flags can also be used in combination with numerical flags, giving rise to additional meanings. For example, the "G" followed by numerical flags indicates longitude, while the "L" flag indicates latitude.

The International Nautical Code also provides for the use of paired alphabetical flags, which take on a different meaning than they do individually. For example, the pairing of flags "A" and "C" means to communicate that you are abandoning ship, while the pair "GW" signals the presence of a man overboard. It is also possible to use the flags as real letters and compose real messages. However, this system is little used because, as you can imagine, it would require the use of many flag letters, thus being impractical.

Sending and receiving messages via flags is regulated and facilitated by some particular flags: the so-called "intelligence" flag and repeater flags. The "intelligence" flag has four distinct functions: if hoisted before the other flags, it indicates that you are responding to the message received and that you have understood the message received. If displayed by the transmitting ship, it signals the end of communication, and finally, it may indicate the separation of the integer part of a number from the decimal part. Repeater flags, on the other hand, are used to duplicate certain characters within a message and thus reduce the number of flags to be used.

Feeling a little confused? This was just a taste of the International Nautical Code, but if you love sailing... this will soon become a breeze!