Inmasat C system is a 2-way messaging system that can send and receive messages/e-mails that are up to 32kb inm length which are from ship-to-shore, shore-to-ship or ship-to-ship. Having been used for a long time, a various number of Inmarsat-C terminals from various suppliers are used on the commercial and naval vessels.

The system uses reliable terminals from various suppliers which is consisted of an omni-directional antenna, transceiver, message interface. The systems which are considered to be GMDSS have additional distress buttons.

Arskom provides Inmarsat-C services for a hundreds of vessels for more than 14 years  with VAS applications such as tracking, LRIT etc.