MCA CoC Marine Communications & GMDSS 2 — Questions and Answers
Question 1: Which four sea areas are defined under the GMDSS?
- A1, A2, A3 and A4 (Correct answer)
- Alpha, Bravo, Charlie and Delta
- Zone 1, Zone 2, Zone 3 and Zone 4
- Inner, Coastal, Offshore and Ocean
Correct answer: A1, A2, A3 and A4
GMDSS defines sea areas A1 (within VHF DSC coverage), A2 (within MF DSC coverage), A3 (within Inmarsat geostationary satellite coverage), and A4 (polar regions beyond A3).
Question 2: What is the function of the COSPAS-SARSAT system in the GMDSS framework?
- To detect and locate distress signals from EPIRBs and PLBs via satellite and alert SAR authorities (Correct answer)
- To provide weather routing information and forecasts to vessels at sea
- To broadcast navigational warnings to ships worldwide
- To control vessel traffic in congested coastal waters
Correct answer: To detect and locate distress signals from EPIRBs and PLBs via satellite and alert SAR authorities
COSPAS-SARSAT is an international satellite system that detects 406 MHz distress signals from EPIRBs and PLBs, computes their position, and relays alert data to SAR authorities.
Question 3: Under GMDSS, what is the minimum number of VHF radiotelephone installations required on a SOLAS vessel on an international voyage?
- Three, of which at least two must be portable handheld units (Correct answer)
- One fixed installation only
- Two fixed installations
- One fixed unit and one portable unit
Correct answer: Three, of which at least two must be portable handheld units
SOLAS requires a minimum of three VHF radiotelephone installations, with at least two being portable handheld radios suitable for use in survival craft.
Question 4: What is the purpose of Maritime Safety Information (MSI) broadcasts?
- To provide navigational warnings, meteorological warnings, and urgent safety information to mariners (Correct answer)
- To transmit commercial shipping schedules to port authorities
- To relay distress messages between vessels and coast radio stations
- To broadcast vessel traffic management instructions in port approaches
Correct answer: To provide navigational warnings, meteorological warnings, and urgent safety information to mariners
MSI broadcasts disseminate navigational warnings, meteorological forecasts, and urgent safety messages to mariners via NAVTEX and Inmarsat SafetyNET to support safe navigation.
Question 5: What watchkeeping requirement applies to DSC on VHF Channel 70 under GMDSS?
- A continuous automatic watch must be maintained at all times while at sea (Correct answer)
- Watch is required only during daylight hours
- Watch is required only when within 20 miles of the coast
- A manual watch for 3 minutes at the start of each watch hour
Correct answer: A continuous automatic watch must be maintained at all times while at sea
GMDSS requires that an automatic, continuous watch be maintained on VHF Channel 70 for DSC distress alerts at all times while the vessel is at sea.
Question 6: What information is automatically encoded in a DSC distress alert transmitted by a GMDSS-equipped vessel?
- MMSI, nature of distress, position, and UTC time of position (Correct answer)
- Vessel name, cargo manifest, and destination port
- Flag state, gross tonnage, and total persons on board
- Call sign, master's name, and next port of call
Correct answer: MMSI, nature of distress, position, and UTC time of position
A DSC distress alert automatically encodes the vessel's MMSI (identity), the selected nature of distress, GPS-derived position, and the UTC time of the last position fix.
Question 7: What does an Inmarsat system provide within the GMDSS framework?
- Satellite communications for distress alerting and general communications in sea area A3 (Correct answer)
- Radar tracking of other vessels within 20 nautical miles
- VHF voice communications with HM Coastguard stations
- Automatic identification of approaching vessels using AIS
Correct answer: Satellite communications for distress alerting and general communications in sea area A3
Inmarsat provides geostationary satellite communications that enable distress alerting, MSI reception via SafetyNET, and general communications for vessels in sea area A3 (approximately between latitudes 70°N and 70°S).
MCA CoC Marine Communications & GMDSS 2
Which four sea areas are defined under the GMDSS?