AIS – the importance of correctly entered manual data

The Automatic Identification System (AIS) is designed to transmit vessel data to other ships and shore stations that are within the VHF-range for information purposes, enhancing the safety of life at sea, the safety and efficiency of navigation, and the protection of the marine environment. 

SOLAS regulation V/19 requires that AIS exchange data ship-to-ship and with shore-based facilities. Therefore, the purpose of AIS is to help identify vessels; assist in target tracking; simplify information exchange; and provide additional information to assist situation awareness. 

AIS should always be in operation when ships are under way or at anchor. However if the Master believes that the continual operation of AIS might compromise the safety of his/her ship, the AIS may be switched off. This might be the case in sea areas where pirates and armed robbers are known to operate. Actions of this nature should always be recorded in the ship's log-book together with the reason for doing so. The Master should, however, restart the AIS as soon as the source of danger has disappeared. In ports AIS operation should be in accordance with port requirements. 

Ships’ officers should ensure that data which is input manually is correctly entered into the AIS - in most cases vessels do have the correct information. However we have received some feedback indicating that this is not always the case - information such as the vessel’s destination, draught, and operational status may not have been correctly updated, which can lead to incorrect assumptions being made by the receivers of AIS information, who may be using this information as a collision avoidance tool.  

The ship should therefore carry out regular routine checks during a voyage to validate the accuracy of the information transmitted. The users must be aware that transmission of erroneous information implies a risk to other ships as well as their own. The users remain responsible for all information entered into the system and the information added by the sensors. 


The potential of AIS as an anti-collision device is recognized and AIS may be recommended as such a device in due time.

Nevertheless, AIS information may be used to assist in collision avoidance decision-making. When using the AIS in the ship-to-ship mode for anti-collision purposes, the following cautionary points should be borne in mind: 

1.   AIS is an additional source of navigational information. It does not replace, but supports, navigational systems such as radar target-tracking and vessel tracking systems (VTS);

2.   The use of AIS does not negate the responsibility of the officer on watch (OOW) to comply at all times with the Collision Regulations.

The user should not rely on AIS as the sole information system, but should make use of all safety relevant information available.' 

INTERTANKO would therefore like to encourage our members to assess the use of AIS onboard their vessels, and especially the information which is manually entered into the AIS by the operators onboard. 

Contact: Fredrik Larsson