When activating a Certus SIM that supports GMDSS (recognizable by the range 8988169727…), the additional ‘Safety’ service will appear in the Service Availability overview.
Here, one can also immediately check if the entered IMEI supports safety (according to Iridium).

If both SIM and terminal support Safety, then the GMDSS options become available in the configuration tab. This consists of two features: The additional Safety Contract selection on the Maritime GMDSS tab and the additional Safety option on the voice line types. The vessel itself needs to match the criteria to allow a Safety contract, that is amongst some other properties mainly the emergency contact details,

It is required to select the appropriate Safety Contract.
Note: if a primary contract is already in place on the Vessel, one cannot provision a second primary contract. The Vessel details do show the latest know situation. If in doubt: when looking up the Vessel in the Vessel management page, the latest situation is fetched from Iridium and the Vessel will be updated.

When a GMDSS is configurated, the first voice line will be configurated as a Safety line by default.

