AIS Class A and Class B, Precautions for using as collision avoidance

AIS Class A and Class B, Precautions for using as collision avoidance

Precautions for using as collision avoidance
Received information depends on the transmitted information.
Position received might not be WGS 84 datum.
AIS information can be wrong.
Some ship doesn’t have AIS.
Some ship might switched off AIS, so avoid over reliance.
For these reasons, for collision avoidance follow colregs.
But it is true, AIS Improve situational awareness and ensure safety of navigation.

Two type AIS – Class A and Class B
Class A type AIS
For SOLAS vessel
All ships 300 gt and above, international voyage
Cargo ships 500 gt and above, not international voyage
Passenger ship of all sizes
Huge functionality
Transmit IMO number, ETA, destination, navigational status, ROT, safety messages (both receive and sending), draft.
Reporting rate more than Class B.
Power: 2 watts and 12 watts
Range: 20 NM

Class B type AIS
For non SOLAS vessel
Pleasure Craft
limited functionality
Does not transmit IMO number, ETA, destination, navigational status, ROT, safety messages (only receive), draft.
Reporting rate less than Class A.
Power: 2 watts
Range: 5-7 NM