Data reporting intervals

AIS information is classed as either static or dynamic. Static information is broadcast, when data has been amended, or upon request, or by default, every 6 minutes.

The reporting rates for dynamic information depend on speed and course change, and are given in the following tables.

Note

The reporting rates shown here are for reference and may not be the rate at which information is actually received by your AIS transceiver. This is dependent on a number of factors, including but not limited to antenna height, gain and signal interference.

Class A systems

Ship’s Dynamic Conditions Reporting rate

At anchor or moored, moving less than 3 knots

  • Not changing course: 3 minutes

  • Changing course: 3 minutes

At anchor or moored, moving greater than 3 knots

  • Not changing course: 10 seconds

  • Changing course: 10 seconds

0-14 knots

  • Not changing course: 10 seconds

  • Changing course: 3 1/3 seconds

14-23 knots

  • Not changing course: 6 seconds

  • Changing course: 2 Seconds

Faster than 23 knots

  • Not changing course: 2 seconds

  • Changing course: 2 seconds

Class B systems

SOTDMACSTDMA

Ship’s Dynamic Conditions Reporting rate (nominal)

SOTDMA – 0 to 2 knots

3 Minutes

SOTDMA – 2 to 14 knots

30 Seconds

SOTDMA – 14 to 23 knots

15 Seconds

SOTDMA – Greater than 23 knots

5 Seconds

CSTDMA – 0 to 2 knots

3 Minutes

CSTDMA – Greater than 2 knots

30 Seconds

Other AIS systems

Source Reporting rate

Search and Rescue (SAR) aircraft

10 Seconds

Aids to Navigation (AToN)

3 Minutes

AIS base station

10 Seconds or 3.33 Seconds, depending on operating parameters