Oversight of the GMDSS

What is GMDSS?

The Global Maritime Distress and Safety System (GMDSS) is an international safety system, which uses satellite and terrestrial technology and ship-board radio systems to prevent accidents from happening and to automatically alert the rescue authorities and nearby vessels quickly in an emergency.

Under the Safety of Life at Sea (SOLAS) Convention, cargo ships of 300 gross tonnage and upwards and all passenger ships on international voyages must be equipped with satellite and radio equipment that conforms to international standards.

In sea areas not covered by terrestrial radio communication systems, the GMDSS depends mostly on satellite communications for allowing seafarers to send distress alerts and receive safety information such as navigational warnings and weather forecasts.

Satellites play a vital role in distress, safety and search and rescue communications as part of the GMDSS. In 2022, over 900 distress alerts were transmitted and over 500,000 messages were broadcast to ships to advise them of weather forecasts and navigational issues.

What is IMSO’s role in GMDSS?

The Organization’s primary purpose is to ensure the provision of maritime mobile satellite communications services for the GMDSS based on the international regulations, standards, recommendations, resolutions and procedures relating to the GMDSS as set out in the relevant Public Services Agreement (PSA) concluded between the Organization and the recognized service providers. The Organization in implementing its primary purpose, performs oversight functions. The oversight functions are executed through regular contingency exercises, continuous monitoring and reporting, and Public Services Committee (PSC) meetings.

In addition, at the request of IMO’s Maritime Safety Committee, the Organization conducts technical and operational assessments of satellite service providers that have applied to have their services recognized for use in the GMDSS. So far, IMSO conducted technical and operational assessments for Iridium, Inmarsat Fleet Safety and BDMSS. Once recognized and all the requirements met, service providers are issued with a Letter of Compliance by the Organization, allowing them to start providing GMDSS service.

Public Services Committees

The Public Services Committees (PSCs) are the official channels of communication between IMSO and the Providers. Their role is to exchange information and views on subjects related to the fulfilment by the Providers of their obligations to IMSO. PSC meetings are held with each of the recognised service providers.

Contingency Exercises

The Contingency Exercises are intended to ensure that the recognized service providers can restore the essential maritime distress and safety services within one hour in the event of satellite or network failures. These services include distress alerting, Search and Rescue (SAR) Co-ordination communications and Maritime Safety Information (MSI) broadcasts.

During the exercises, IMSO observes the effective execution of the contingency procedures, with specific attention on critical items, such as:
• The capabilities of the Network Operations staff conducting the exercise
• High-level decision-making at the start of the exercise
• Participation by relevant satellite and ground station operators
• Functional notification system
• Any issues with the procedure being used

Continuous reporting

The service providers have an obligation to report any planned or unplanned outages to IMSO (no later than 24 hours for unplanned outages and at least 24 hours before the planned outages). IMSO keeps a record of these outages and request follow-up information if needed. A typical outage report would include the following:
• Start and end date/time
• Affected services
• Description of the outage, including the component causing the outage
• Corrective action