GROL Distress, Urgency and Safety Communications (GMDSS)

Question 1

Which spoken signal begins a radiotelephone URGENCY message, such as one about a person overboard where the vessel is not in grave and imminent danger?

Accepted Answer

PAN-PAN

Answer

PAN-PAN, spoken three times, is the urgency signal. It ranks below MAYDAY, which is for grave and imminent danger, and above SECURITE, which is for safety and navigation warnings.

Question 2

On which VHF marine channel is Digital Selective Calling (DSC) used for distress, urgency and safety alerts?

Accepted Answer

Channel 70

Answer

VHF Channel 70 (156.525 MHz) is set aside only for DSC digital alerting. Voice is not allowed on it. Follow-up voice traffic happens on Channel 16.

Question 3

What is the frequency of VHF marine Channel 16, the international voice distress, safety and calling channel?

Accepted Answer

156.800 MHz

Answer

Channel 16 is 156.800 MHz. Stations monitor it for distress, safety and calling. 121.5 MHz is the aeronautical emergency frequency.

Question 4

A Search and Rescue Radar Transponder (SART) shows up on a rescue vessel's radar display when interrogated by radar in which band?

Accepted Answer

9 GHz X-band

Answer

A radar SART responds to 9 GHz (X-band, about 9.2–9.5 GHz) marine radar. It shows as a line of 12 dots pointing toward the survival craft's position.

Question 5

What frequency do modern satellite EPIRBs use to send their distress alert to the COSPAS-SARSAT system?

Accepted Answer

406 MHz

Answer

Satellite EPIRBs transmit a coded digital distress message on 406 MHz to COSPAS-SARSAT satellites. Many also send a low-power 121.5 MHz homing signal for final location.

(GROL) General Radiotelephone Operator License Practice Test

(GROL) General Radiotelephone Operator License Practice Test

GROL Distress, Urgency and Safety Communications (GMDSS)