AIS dynamic data is checked through routine bridge checks and corroboration with visual and radar observations. AIS dynamic data includes position with accuracy and integrity indications, a UTC position timestamp, course over ground, speed over ground, heading, navigational status and rate of turn where available. The officer of the watch should periodically check own-ship position, speed over ground and sensor information. Regular routine checks should also validate the accuracy of information being transmitted.
A missing sensor may cause AIS to transmit a not-available value. An inaccurate connected sensor may instead supply plausible but incorrect data that the built-in integrity test does not validate.
AIS information should be corroborated through systematic visual and radar observation. It must not replace lookout, radar plotting or the use of all available means.
