What are AIS reporting intervals?
The different information types are valid for different time periods and thus need different update intervals.
Static information: Every 6 min or when data has been amended and when interrogated. The long interval between transmissions of static information is the reason, why other AIS stations are only seen with their MMSI when an AIS is switched on until the first report with static information is received.
Dynamic information: Dependent on speed and course alteration according to the tables below.
Voyage related information: Every 6 min or when data has been amended and when interrogated.
Safety related messages: As required.
Class A reporting intervals:
|Dynamic conditions||Nominal reporting interval|
|Ship at anchor or moored and not moving faster than 3 knots||3 min|
|Ship at anchor or moored and moving faster than 3 knots||10 s|
|Ship 0-14 knots||10 s|
|Ship 0-14 knots and changing course||3 1/3 s|
|Ship 14-23 knots||6 s|
|Ship 14-23 knots and changing course||2 s|
|Ship > 23 knots||2 s|
|Ship > 23 knots and changing course||2 s|
Other AIS Devices’ reporting intervals:
|Platform’s condition||Nominal reporting interval||Increased reporting interval|
|Class B “SO” not moving faster than 2 knots||3 min||3 min|
|Class B “SO” moving 2−14 knots||30 s||30 s|
|Class B “SO” moving 14−23 knots||15 s||30 s|
|Class B “SO” moving > 23 knots||5 s||15 s|
|Class B “CS” not moving faster than 2 knots||3 min||–|
|Class B “CS” moving faster than 2 knots||30 s||–|
|Search and rescue aircraft (airborne mobile equipment)||10 s||–|
|Aids to navigation (AIS AtoN)||3 min||–|
|AIS base station||10 s||–|
The increased reporting intervals are used in a crowded area (more than 50% of the slots used).