Is there a rule that the signal flag on a seagoing ship must be raised to the top?

? There is no rule that the signal flag on a seagoing ship must be raised to the top.

The international maritime signal flag is an international communication flag, which consists of 40 flags, including 26 alphabet flags, 10 digital flags, 3 representative flags and 1 reply/abbreviation flags.

In addition to the combined information, each flag has its representative significance, including various situations of maritime navigation. As long as the representative flag indicating the situation is displayed, the trustee can grasp the dynamics of the ship.

This way of communication can cross language barriers and clearly convey intentions, so it has become a unified signal language in the world. It has also become a kind of "semaphore". On warships and merchant ships equipped with advanced communication equipment such as VHF wireless telephone, global maritime distress and safety system (GMDSS) and satellite telephone, the semaphore is still used as the simplest and reliable communication means.

Logo collection and communication:

Flag communication is usually hung one at a time, and the receiving ship (shore platform) will descend after answering. The reading order is: mast first, horizontal Zhang Suo between masts later, and transverse truss last (first right then left, first outside and then inside).

In the process of calling and answering, if the sending ship doesn't know the call sign of the other party, the sending ship directly hangs the flag to communicate. After seeing the signal, all ships around should fly the response flag at half mast, and when the sender's intention is fully understood, all the response flags will be raised. Or the ship can be hung with a "VF" code group, which means "it's time for you to hang the call sign".

If you know the call sign of the other party, hang the call sign of the receiving ship first, and then hang the signal flag code group of your own message in turn (if the weather permits, you can also hang it all at once).