Automatic Identification Systems (AIS)

This information is current as of July 2010.


An Automatic Identification System (AIS) uses the VHF radio broadcasting system to transfer packets of data over the VHF data link. It enables AIS equipped vessels and shore-based stations to automatically send and receive identification information that can be displayed on an electronic chart, computer display or compatible radar.

Information provided includes the ship’s name, call sign and other identifying features, such as type of vessel, course and speed over the ground, heading and rate of turn for selected vessels.

There are two types of AIS:

  • Class A has been mandated by the International Maritime Organization (IMO) for SOLAS vessels
  • Class B is not mandated by the IMO and has been developed for non-SOLAS commercial and recreational vessels.

This information focuses on Class B AIS.


  • Improves your ability to follow the movements of other vessels and for other masters to follow your vessel, particularly at night
  • When used with an appropriate graphical display, AIS provides fast, automatic and accurate information about the risk of collision
  • Enables you to identify, and communicate with, targeted vessels
  • Displays dynamic data, such as details of the voyage and draught.


  • May cause you to become more focused on the graphical displays, rather than on keeping a proper lookout
  • The glow from the screen may cause temporary visual impairment at night, which may hamper decision making
  • Errors resulting from improper equipment settings may lead to an incident
  • Does not replace your responsibility to display good seamanship practices
  • May not be suitable for open runabouts and similar vessels.

Indicative costs

Class B AIS can cost between $1,500 to $2,500 per unit, plus installation costs of around $500.


Class B AIS are not mandatory for recreational and small commercial vessels being operated on NSW navigable waters.

More information

More information about AIS is available from the Australian Maritime Safety Authority.

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