Modernized GMDSS Requirements under SOLAS: What Shipowners Need to Know

The IMO's modernized Global Maritime Distress and Safety System (GMDSS) requirements, adopted through Resolution MSC.496(105), have been mandatory since 1 January 2024. The amendments update SOLAS radiocommunication rules, support modern communication systems and remove obsolete provisions.

The International Maritime Organization (IMO) has completed a major modernization of the Global Maritime Distress and Safety System (GMDSS), the international framework that supports distress alerts, maritime safety information and search-and-rescue communications at sea.

The key amendments were adopted by the Maritime Safety Committee through Resolution MSC.496(105) and entered into force on 1 January 2024. They revise SOLAS Chapters II-1, III, IV and V, together with the appendix on certificates, and introduce consequential updates to related mandatory instruments, performance standards and guidance.

What has changed?

The revised framework is designed to make SOLAS technology-neutral and ready for new communication services. It removes obsolete carriage requirements, clarifies functional requirements for distress and safety communications, and enables future recognition of modern satellite and terrestrial communication systems within the GMDSS.

Practical implications for shipowners and operators

Shipowners, managers and technical departments should review the vessel's radio installation, statutory certificates, equipment manuals and maintenance arrangements against the revised SOLAS Chapter IV requirements. Particular attention should be given to the ship's sea area, availability of approved service providers, reception of Maritime Safety Information, reserve sources of energy and the ability to transmit and receive distress alerts through the required communication channels.

IMO Circular MSC.1/Circ.1676 also recognizes the transitional availability of certain newly standardized equipment. Administrations may permit, until 1 January 2028, the continued installation of specified VHF, MF/MF-HF and Inmarsat-C equipment complying with the earlier performance standards described in the circular. Owners should therefore confirm the applicable acceptance criteria with the vessel's flag Administration and classification society before purchasing or replacing equipment.

Why compliance matters

GMDSS equipment is a critical safety system. Correct selection, installation, testing and maintenance help ensure that a vessel can alert rescue authorities, communicate with ships and shore stations, and receive urgent navigational and meteorological warnings during an emergency.

Big Sea JSC recommends that vessel operators plan radio surveys and equipment upgrades early, keep service records current, and coordinate any modification with authorized technicians, the flag Administration and the classification society.

Official references:
• IMO – Radiocommunications: https://www.imo.org/en/ourwork/safety/pages/radiocommunications-default.aspx
• IMO Resolution MSC.496(105) – SOLAS amendments
• IMO Circular MSC.1/Circ.1676 – Availability of GMDSS equipment after 1 January 2024

Disclaimer: This article provides general information only. Requirements may vary according to vessel type, sea area, flag Administration and classification society.