What is required for GMDSS vessels in Sea Areas A2, A3, or A4?

The requirement for GMDSS vessels in Sea Areas A2, A3, or A4 to maintain a continuous DSC watch on 2187.5 kHz when underway is essential for ensuring effective maritime communication and safety. This frequency is designated for Digital Selective Calling (DSC) distress and safety communications, which allows vessels to send automated distress alerts and receive important safety information.

Maintaining a watch on this frequency ensures that a vessel can quickly respond to distress situations and can also be alerted to any safety messages broadcasted in the area. In Sea Areas A2, A3, or A4, which may experience limited VHF coverage or be outside Inmarsat satellites' footprint, having a reliable means of distress communication is vital. This regulation reinforces the commitment of the GMDSS to provide continuous communication capabilities, thereby enhancing maritime safety in these regions.

Other options do not capture the necessary requirement for continuous watch, as they either specify conditions under which communication is required or focus on regions that don't equate to the broader GMDSS watch obligations. Having the continuous watch on 2187.5 kHz is a proactive measure, ensuring that vessels are prepared to receive and respond to time-sensitive safety information at all times while underway