Which frequencies and modes are allocated for Distress alerting in GMDSS?

The correct response identifies the designated frequencies and modes specifically allocated for distress alerting within the Global Maritime Distress and Safety System (GMDSS).

To break down the components mentioned:

• 406 MHz via EPIRB: The 406 MHz frequency is used for emergency position-indicating radio beacons (EPIRBs), which are key for alerting search and rescue services during a maritime emergency.

• 1626.5-1645.5 MHz via Inmarsat: This frequency range is associated with the Inmarsat system, which provides satellite communications for distress alerts. It is crucial for ensuring that vessels can communicate distress messages when they are out of VHF range.

• Channel 70 DSC: The Digital Selective Calling (DSC) on VHF Channel 70 is specifically allocated for distress, urgency, and safety communications, making it part of the essential framework for alerting in emergencies.

• Six MF/HF DSC frequencies: These frequencies provide additional methods for implementing distress alerts over Medium Frequency (MF) and High Frequency (HF) radio frequencies, ensuring robust communication options for vessels at sea.

By incorporating the specified frequencies and systems, the correct answer accurately identifies the full scope of distress alert