Audible warning systems are the systems that give a warning by making a sound when necessary. Horn, buzzer, whistle, siren are some of them. Seafarers need to be familiar with the principles of the use of audible warning equipment for the safety of the course of navigation. The captain should be able to signal when necessary. The audio devices are functional in locating the boat. Also, sound equipment is important for determining the position of the boat in emergencies. Audio signals have specific rules. These signals consist of long and short whistles. These signals are used functionally when boats change direction. The shorthorn or horn will sound for 1 second and the longhorn or horn will sound for 4 or 6 seconds. They have universal meanings. Knowing them well will benefit the boat and sailor in case of danger. These rules are briefly as follows: 

• If 1 short whistle is played, this means ''I'm turning the course of the ship or boat to starboard. ''

• If 2 short whistles are played, this means '' I'm heading towards the pier.'' 

• 3 short whistles mean ''I'm making a lathe...''.

The acoustic signals inform the environment about the maneuver and position in foggy weather and when the viewing distance is too low. There are some sound warning rules for warning other boats and emergencies. These rules are functional for the comfort of emergencies. Audible warning systems ensure the safety of boats with many benefits.