What is AIS ?
AIS stands for Automatic Identification System. It was introduced by the IMO (International Maritime Organization) to improve safety in the maritime traffic. All ships equipped with AIS transponders exchange their current movement data such as position, course and speed as well as other additional information via the VHF channels 87B and 88B. In professional shipping, the system is already part of the equipment requirements for SOLAS (Safety of Life at Sea).
Do all ships transmit AIS data ?
For vessels on international voyages AIS is mandatory from the registered tonnage (RT) of 300. For vessels on national voyages it is mandatory from 500 RT. For passenger ships the regulation is as follows:
All passenger ships and all other ships with registered tonnage >300 RT since 2004
All passenger ships and all other ships with registered tonnage >500 until 1. July, 2008.
What kind of information is transmitted over AIS ?
Vessel name, callsign, MMSI number (user ID), IMO number, position, course over ground, speed over ground, true heading, rate of turn, length, beam, draught, type of vessel, navigational status, destination and estimated time of arrival.