Types of AIS

AIS units can be carried on board vessels and aircraft to support maritime safety and search and rescue operations. There are many different types of AIS units and stations:

• AIS units are carried on board vessels
• AIS carried on board aircraft to support maritime safety
• AIS base stations are non-shipborne stations which can relay information from AtoN and vessels
• AIS AtoN which can be a physical aid to navigation or a virtual aid which broadcasts information
• AIS search and rescue transmitters (SART) which are self-contained radio devices used to locate a survival craft or vessel in distress by sending updated position reports
• AIS man overboard units which are designed to be carried by your crew and used in the event of a man overboard situation or other personal emergency.

AIS on board vessels can be classified as Class A and Class B.

AIS class A

AIS is included in the International Convention for the Safety of Life at Sea (SOLAS) convention for: vessels are:

• vessels of 300 gross tonnage and upwards engaged on international voyages
• vessels of 500 gross tonnage and upwards not engaged on international voyages
• passenger ships irrespective of size.

The AIS referred to in the SOLAS convention is often termed ‘AIS Class A’.

AIS class B

AIS Class B is intended for use on non-SOLAS vessels. These can include domestic commercial vessels and pleasure craft.

AIS Class B units have less functionality than Class A units but they operate and communicate with AIS Class A units and other types of AIS units.

Receive only AIS units

Receive only AIS units will pick up transmissions but they won't transmit any information. Using this unit means you will see other vessels but you won't be seen. Receive only AIS units do not need an MMSI.