The Merchant Shipping Directorate would like to draw the attention of all concerned to the Marine Safety Investigation Report No. 07/2020, highlighting the potential safety risks involved in VHF radio communication between vessels and reliance on AIS information, for the purpose of collision avoidance.
There has been a significant number of collisions due to the misuse of VHF radio equipment and AIS. For this reason, the use of these equipments for the purpose of anti-collision is strongly discouraged. Anti-collision measures agreed upon via VHF radio communications may not always be appropriate and because of this, a catastrophic situation may occur.
On the other hand, although AIS equipment provides additional navigation information for collision avoidance decision making, it is not a replacement for other navigational and anti-collision information which is derived from marine radar plotters or other methods of systematic observation.
The primary electronic anti-collision instruments are Radar and ARPA. Due to the high risk of confusion, misunderstandings and misinterpretation, VHF radio and AIS should not be relied upon singularly for collision avoidance.
Further information on the risks can be found in this Merchant Ship Directorate.