Maritime safety

Why seafarers rely on Inmarsat

Safety is in our DNA – we were set up in 1979 by the International Maritime Organization (IMO) to provide reliable satellite safety communications.

When disaster strikes – a catastrophic storm, a collision, a medical emergency – mariners know that they can rely on our safety services to get help fast.

We’ve continued to ensure our safety services go above and beyond the IMO’s Safety of Life at Sea (SOLAS) and Global Maritime Distress and Safety System (GMDSS) requirements – by, for example, exceeding the demand for satellite and ground network availability of 99.9 per cent.

Today, over our L-band network, we support both SOLAS and non-SOLAS vessels and some 1.5 million seafarers depend on us for a communications lifeline that is reliable and unaffected by bad weather.

Inmarsat shore-to-ship Maritime Safety Information urgency and distress priority communications are free of charge.

What is the GMDSS?

The 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 300GRT and upwards and all passenger ships on international voyages must be equipped with satellite and radio equipment that conforms to international standards.

Inmarsat is currently the only provider of GMDSS-approved satellite communication services. Our Inmarsat C and Fleet 77 services have been keeping 1.5 million seafarers safe at sea every day since the inception of GMDSS in 1999.

In May 2018, Fleet Safety, our next generation satellite safety service delivered over FleetBroadband and Fleet One, received formal GMDSS recognition by the IMO, marking the most significant advance in maritime safety for a generation.

One-touch distress alerts

Ships with GMDSS-compliant Inmarsat terminals can send an alert by pressing a Dedicated Distress Button (DDB). This gets the highest priority over the Inmarsat network and is automatically routed to an on-shore Maritime Rescue Co-ordination Centre (MRCC). Ships can also send prioritised distress messages, with more details.

Our satellite communications systems make it possible for an MRCC to contact the ship sending a distress alert to verify that it is not a false alarm before they trigger a search and rescue operation.

Our FleetBroadband Voice Distress service provides priority call access, interrupting all non-emergency calls as soon as the Dedicated Distress Button is pressed. The ship is connected to an operator at one of four MRCCs strategically located around the globe. This service is enabled by fitting an equipment add-on to Cobham SATCOM’s SAILOR FleetBroadband terminal or JRC FleetBroadband systems. Urgency priority calls to an MRCC for medical advice, medical assistance and maritime assistance can also be made via our 2-digit dial codes free of charge.

All FleetBroadband terminals support as standard the free 505 Emergency Calling service, which routes a call to the appropriate MRCC but does not have priority over other voice traffic. To be put straight through to search and rescue, mariners simply dial 505 (just think SOS).

SafetyNET II

SafetyNET II is the new generation international broadcast and automatic reception service for Maritime Safety Information (MSI), released in November 2017.  SafetyNET II allows Maritime Safety Information Providers (MSIPs) worldwide to transition to web-based messaging and provides the critical link to upgrading Global Maritime Distress and Safety System (GMDSS) capability.

SafetyNET II is an enhancement to the existing SafetyNET system and provides an interactive web interface for Maritime Safety Information Providers (MSIPs) to create their Maritime Safety Information (MSI) messages and deliver them over multiple systems simultaneously, including Inmarsat C, Mini C, and Fleet Safety.

So what’s new?

  • Easy to use web-based user interface
  • Transmitted over the Inmarsat-4 satellite constellation
  • Broadcast over Inmarsat C, Mini C and Fleet Safety terminals
  • Optional MSI message monitoring and cancellation
  • Enhanced broadcast scheduling
  • Internal application and geographical redundancy built in Maritime Safety Servers (MSS)
  • Single billing
  • No extra equipment needed


Our new custom web application, specifically designed for Maritime Rescue Coordination Centres (MRCCs), brings current and new MRCC functions into one interactive platform to enable easier co-ordination of a Search and Rescue operation.

  • Reception of Distress Alerts
  • Simultaneous broadcast of Distress Alert Relay to Inmarsat C, Mini C and Fleet Safety
  • Broadcast Search and Rescue co-ordination messages to rectangular/circular area to Inmarsat C, Mini C and Fleet Safety
  • Priority Messaging ship-to-shore and shore-to-ship
  • Innovative Distress Chat
  • MRCC and vessel lookup functions
  • Nearby vessel search
  • Secure web application – no specialist equipment required

Distress Chat enables an MRCC to control a Search and Rescue incident using the facilities available on RescueNET. By accessing Distress Chat, the MRCC can communicate in real time with multiple vessels and multiple MRCCs using FleetBroadband while having complete control over who joins and leaves the operational chat session.

RescueNET is available free of charge to all authorised, certified and GISIS (Global Integrated Shipping Information System) registered MRCCs.  For more information contact us at

Related services

» Inmarsat C
» Inmarsat Fleet F77


505 and voice distress FAQs

Maritime Rescue Co-ordination Centres 

Distress alerts 

Enhancing maritime security

Useful contacts



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