Guidance on the validity of radiocommunications equipment installed and used on ships

The International Maritime Organization has released Guidance on the validity of radiocommunications equipment installed and used on ships.

The Maritime Safety Committee, at its 107th session (31 May to 9 June 2023), approved the guidance set out in the following paragraphs, taking into account concerns over the availability of VHF radiocommunication equipment compatible with the frequencies and channelling arrangements set out in Appendix 18 of the ITU Radio Regulations (RR) – Edition 2020.

This guidance recognizes that incompatibility may exist between VHF radiocommunication equipment installed on ships and on shore, and the revised frequencies and channelling arrangements in Appendix 18 of the RR.

This circular replaces MSC.1/Circ.1460/Rev.3, which indicated the need for updating existing VHF radiocommunication equipment following the first radio survey after 1 January 2024.

The ITU World Radiocommunication Conferences in 2012, 2015, and 2019 made extensive changes to Appendix 18 of the RR.

While these changes do not affect the Global Maritime Distress and Safety System (GMDSS), they do affect the use of other frequencies used for VHF meteorological, navigational, and urgent marine information broadcasts, port operations, and Vessel Traffic Service (VTS).

According to the Performance standards for shipborne VHF radio installations capable of voice communication and digital selective calling (resolution MSC.511(105)), VHF radiocommunication equipment should comply with the RR.

The Guidance on procedures for updating shipborne navigation and communication equipment (MSC.1/Circ.1389) notes that updates to application software and firmware to meet changes in IMO and ITU regulatory requirements are needed.

To ensure GMDSS communication capability and the availability of appropriate GMDSS radiocommunication equipment, and without prejudice to the arrangements contained in Appendix 18 of the RR, VHF radiocommunication equipment should be updated following the first radio survey after 1 January 2028, at the earliest, so that it meets the arrangements that will be in force by then.

Member States are invited to bring this information to the attention of the appropriate national authorities and all other parties concerned.

MSC.1/Circ.1460/Rev.4 was released on 30 June 2023.


For more information, please see the document below (available only to subscribers):


Guidance on the validity of radiocommunications equipment installed and used on ships