GMDSS GMDSS Frequencies and Radio Bands 1 — Questions and Answers
Question 1: What is the international VHF distress, safety, and calling frequency used in GMDSS?
- Channel 16 (156.8 MHz) (Correct answer)
- Channel 22A (157.1 MHz)
- Channel 70 (156.525 MHz)
- Channel 6 (156.3 MHz)
Correct answer: Channel 16 (156.8 MHz)
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?
- 156.8 MHz (Ch 16)
- 156.525 MHz (Ch 70) (Correct answer)
- 157.1 MHz (Ch 22A)
- 156.3 MHz (Ch 6)
Correct answer: 156.525 MHz (Ch 70)
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?
- 2182 kHz (Correct answer)
- 4125 kHz
- 2187.5 kHz
- 518 kHz
Correct answer: 2182 kHz
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?
- 2182 kHz
- 2187.5 kHz (Correct answer)
- 2174.5 kHz
- 4210 kHz
Correct answer: 2187.5 kHz
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?
- 490 kHz
- 518 kHz (Correct answer)
- 4209.5 kHz
- 2174.5 kHz
Correct answer: 518 kHz
518 kHz is the primary international Navtex frequency used for maritime safety information broadcasts in English.
Question 6: Which HF frequency band is commonly used for long-range GMDSS DSC distress alerting?
- 4 MHz band (4207.5 kHz) (Correct answer)
- 27 MHz band
- 1.6 MHz band
- 40 MHz band
Correct answer: 4 MHz band (4207.5 kHz)
The 4 MHz HF band, specifically 4207.5 kHz, is one of the designated HF DSC distress frequencies for long-range communications.
GMDSS GMDSS Frequencies and Radio Bands 1
What is the international VHF distress, safety, and calling frequency used in GMDSS?