Marine Communications & GMDSS Flashcards

What does GMDSS stand for?

Answer: Global Maritime Distress and Safety System

GMDSS stands for Global Maritime Distress and Safety System, the internationally mandated framework for maritime emergency and safety communications.

Which VHF channel is exclusively designated for DSC distress alerting under GMDSS?

Answer: Channel 70

VHF Channel 70 is reserved exclusively for Digital Selective Calling (DSC) distress alerts; voice distress communications then take place on Channel 16.

What frequency does the international NAVTEX service use to broadcast Maritime Safety Information?

Answer: 518 kHz

NAVTEX broadcasts Maritime Safety Information (MSI) on 518 kHz in the medium frequency band, automatically received by vessels equipped with a NAVTEX receiver.

What is the primary purpose of an EPIRB?

Answer: To transmit a distress signal and vessel position to SAR authorities via satellite

An EPIRB (Emergency Position-Indicating Radio Beacon) transmits a distress signal to COSPAS-SARSAT satellites, alerting SAR authorities and providing the vessel's position.

In which GMDSS sea areas is a satellite EPIRB mandatory for SOLAS vessels?

Answer: A3 and A4

GMDSS sea areas A3 and A4 lie beyond the coverage of MF and VHF coastal stations, so vessels trading there must carry a satellite EPIRB to ensure global distress alerting capability.

What is a SART and on what frequency does it operate?

Answer: A Search and Rescue Transponder responding to 9 GHz X-band radar pulses

A SART (Search and Rescue Transponder) responds to 9 GHz X-band radar transmissions from searching vessels or aircraft, displaying a distinctive line of blips on the radar screen.

What MF frequency is internationally reserved for DSC distress alerting?

Answer: 2187.5 kHz

2187.5 kHz is the internationally designated MF frequency for DSC distress alerts under GMDSS, while the legacy voice distress frequency 2182 kHz is used for subsequent distress traffic.