Below you will find the "International Code Of Signals Flags" which were used to communicate messages by making up words using flags. This method of communication has reduced in popularity since the advent of VHF radio, AIS and mobile phones. However some code flags are reguarly seen on vessels such as "A", "B" and "H" to denote the meanings listed below.
I am engaged in diving operations. keep well clear at slow speed.
I am taking in, or discharging, or carrying dangerous goods.
I am maneuvering with difficulty, Keep clear of me.
I am altering my course to starboard.
I am disabled, communicate with me.
I require a pilot.
I have a pilot on board.
I am altering my course to port.
keep clear, I am on fire and have dangerous cargo aboard.
I wish to communicate with you.
You should stop your vessel immediately.
My vessel is stopped and making no way through the water.
No or negative.
Proceeding to sea, all crew return to ship.
Request clearance into port.
My vessel is going astern.
My vessel is engaged in trawling operations, keep clear
You are running into danger.
I require assistance.
I require medical assistance.
Stop carrying out your intentions and watch for my signals.