Amendments to SOLAS Chapter IV: Modernization of the GMDSS

The modernization of the Global Maritime Distress and Safety System (GMDSS) is governed by the amendments to SOLAS Chapter IV, adopted under Resolution MSC.496(105). To ensure a uniform transition, the IMO has issued technical guidance through COMSAR.1/Circ.32/Rev.3, providing detailed requirements for the installation and validity of radiocommunication equipment. Furthermore, all installations must strictly adhere to the newly adopted MSC Performance Standards.

1. Implementation Dates

• Performance Standards: Radio equipment installed on or after 1 January 2024 must conform to the revised Performance Standards adopted by the Organization.
• Application: Applies to all passenger ships and cargo ships (> 300 GT). 
• Transition Provisions: Radio equipment installed before 1 January 2024 shall continue to comply with the relevant performance standards not inferior to those adopted by the Organization prior to that date.

2. Impact on Shipowners

• A3 Area: The definition is now technology-neutral. It refers to an area, excluding sea areas A1 and A2, within the coverage of RMSS supported by the ship earth station (SES) carried on board. Owners can now utilize either Inmarsat or Iridium.
• Direct-Printing Telegraphy (NBDP): NBDP is no longer a mandatory requirement for distress and safety communications in Sea Areas A3 and A4.
• Existing ships: Compliance and certificate updates required by the first Radio Survey after 1 January 2024.
• Survey and Certification: Existing vessels must ensure compliance by the first Periodical Radio Survey after 1 January 2024. The Record of Equipment (Form R, P, or C) must be updated to reflect the specific RMSS utilized.

3. Impact on Technical Clauses in Shipbuilding Contracts

Specifications must explicitly define the selected RMSS provider to ensure compatible antenna arrangements, power supply, and integrated bridge system (IBS) layouts.

Performance standards shall be in accordance with the latest applicable IMO Resolutions and guidelines

Requirements for dedicated NBDP terminals should be omitted unless requested for non-GMDSS commercial purposes, allowing for reduced bridge console footprint.

NOTE: As per MSC.1/Circ.1676, VHF, MF và MF/HF và Inmarsat-C approved under legacy standards may still be installed until 1 January 2028, provided such installation is authorized by the Maritime Administration.