GMDSS Standards of Training, Certification and Watchkeeping for Seafarers (STCW) General Operator's Certificate (GOC) FCC Element 7 Practice Test

Inmarsat safety communications for Distress alerting operate over a dedicated satellite link in the L-band. The specific frequency range used for these distress alerts is 1626.5 to 1645.5 MHz. This band is allocated for ship-to-satellite safety communications within the Inmarsat system, which allows the distress alert to reach MRCC quickly through the satellite network.

The other options correspond to different systems or services: 406 MHz is for COSPAS-SARSAT distress beacons; 2182 kHz is the traditional maritime MF distress voice channel; and 2174.5 kHz is an HF frequency not used for Inmarsat distress alerts.