GMDSS GMDSS Frequencies and Radio Bands

Question 1

What is the international VHF distress, safety, and calling frequency used in GMDSS?

Accepted Answer

Channel 16 (156.8 MHz)

Answer

Channel 16 at 156.8 MHz is the designated international VHF distress, safety, and calling frequency maintained by all GMDSS-equipped vessels.

Question 2

Which frequency is designated for Digital Selective Calling (DSC) on VHF?

Accepted Answer

156.525 MHz (Ch 70)

Answer

VHF Channel 70 at 156.525 MHz is the dedicated DSC frequency used for automated digital distress and safety alerting.

Question 3

What is the MF distress and calling frequency used for voice (radiotelephone) in GMDSS?

Accepted Answer

2182 kHz

Answer

2182 kHz is the international MF radiotelephone distress and calling frequency used for voice communications in GMDSS.

Question 4

Which MF frequency is used for DSC distress alerting?

Accepted Answer

2187.5 kHz

Answer

2187.5 kHz is the international MF DSC frequency used to transmit digital selective calling distress alerts.

Question 5

What frequency is used for Navtex broadcasts in the US and Western Atlantic?

Accepted Answer

518 kHz

Answer

518 kHz is the primary international Navtex frequency used for maritime safety information broadcasts in English.

GMDSS - Global Maritime Distress and Safety System Practice Test