Horn

The ship’s horn is used to communicate with other vessels. In particular to let other craft know which way they are planning on going - i.e. passing on the port or starboard sign. The benefits of using a horn for this type of communication is that it doesn’t rely on technology and is therefore less prone to have issues. They are also able to be heard when there is poor visibility or at night.

A different number of blasts on the horn relays different messages pertaining to the ship’s planned movement, however the horn may also be used to indicate an emergency or even as a greeting to other vessels or embarking or disembarking passengers.