• Safety of life at sea
  • Safety and efficiency of navigation
  • Protection of the marine environment

The purpose of AIS is to help identify vessels, assist in target tracking, simplify information, exchange and provide additional information to boost situational awareness. In general, data received via AIS will improve the quality of information to assist situation awareness as well as improve the quality of the information to the OOW.

The principle of AIS is to allow automatic exchange of shipboard information from the vessel’s sensors – inputted static and voyage related data – between one vessel and another and between a vessels and a shore station(s).

The Automatic Identification System (AIS) is a system used by ships and Vessel Traffic Services (VTS) principally for identification and locating vessels. AIS provides a means for ships to electronically exchange ship data including: identification, position, course, and speed, with other nearby ships and VTS stations. This information can be displayed on a screen or an ECDIS display. AIS is intended to assist the vessel's watchstanding officers and allow maritime authorities to track and monitor vessel movements. It works by integrating a standardized VHF transceiver system with an electronic navigation system.

AIS is used in navigation primarily for collision avoidance.

In busy waters and harbors, a local Vessel Traffic Service (VTS) may exist to manage ship traffic. In busy waters and harbors, a local Vessel Traffic Service (VTS) may exist to manage ship traffic. AIS was developed with the ability to broadcast positions and names of things other than vessels, namely it can serve to transmit navigation aid and marker positions. Its principal functions are to facilitate:
    Information exchange between vessels within VHF range of each other, increasing situational awareness management in congested waterways.
    Automatic reporting in areas of mandatory and voluntary reporting.
    Exchange of safety related information between vessels and shore station(s).

Chapter V of the 1974 SOLAS Convention [1] requires mandatory carriage of AIS equipment on all vessels constructed after 1 July 2002. Implementation for other types and sizes of SOLAS Convention vessels was required to be completed not later than 31 December 2004. The IMO Performance Standards for AIS states that:
The AIS should improve the safety of navigation by assisting in the efficient navigation of ships, protection of the environment, and operation of Vessel Traffic Services (VTS), by satisfying the following functional requirements:

Before using shipborne AIS, the user should fully understand the principle of the current Guidelines and become familiar with the operation of the equipment, including the correct interpretation of the displayed data.