Inmarsat C is a two-way store and forward communication system that transmits messages in data packets in ship-to-shore, shore-to-ship and ship-to-ship direction.

Inmarsat C comprises of a small omnidirectional antenna, compact transceiver (transmitter and receiver), messaging unit and, if GMDSS-compliant or with a distress function, a Dedicated Distress Button to activate a Distress Alert.

To protect crew and vessels, modern Inmarsat C terminal includes an integrated Global Navigational Satellite Services (GNSS) receiver, providing automatic terminal position updates and reporting when a distress alert is initiated. The vessel’s position data (position, course and speed) is shared with reporting applications.