STCW Communication Systems 2 — Questions and Answers
Question 1: What is the primary purpose of the NAVTEX system in maritime communications?
- To transmit navigational and meteorological warnings automatically (Correct answer)
- To establish voice contact with coast guard stations
- To send distress signals via satellite
- To coordinate VHF channel usage between vessels
Correct answer: To transmit navigational and meteorological warnings automatically
NAVTEX automatically broadcasts navigational warnings, weather forecasts, and urgent maritime safety information on 518 kHz.
Question 2: Which ITU radio region covers the United States for maritime communications purposes?
- Region 1
- Region 2 (Correct answer)
- Region 3
- Region 4
Correct answer: Region 2
The United States falls within ITU Radio Region 2, which covers the Americas.
Question 3: In the GMDSS, what does the term 'SAR' stand for?
- Signal Amplification and Relay
- Search and Rescue (Correct answer)
- Satellite Alerting and Response
- Station Authentication Record
Correct answer: Search and Rescue
SAR stands for Search and Rescue, a core function supported by the GMDSS communication framework.
Question 4: What is the maximum effective range of a typical handheld VHF radio under ideal conditions?
- 5-10 nautical miles (Correct answer)
- 25-50 nautical miles
- 100-150 nautical miles
- 200+ nautical miles
Correct answer: 5-10 nautical miles
Handheld VHF radios typically achieve 5-10 nautical miles range due to their low power output and VHF line-of-sight propagation.
Question 5: Which frequency band is used by INMARSAT for satellite communications?
- HF (3-30 MHz)
- VHF (30-300 MHz)
- L-band (1-2 GHz) (Correct answer)
- X-band (8-12 GHz)
Correct answer: L-band (1-2 GHz)
INMARSAT satellite communications primarily operate in the L-band frequency range (1-2 GHz).
Question 6: What is the function of a 406 MHz EPIRB in the GMDSS?
- To provide two-way voice communication with rescue services
- To transmit a distress alert with vessel identity to COSPAS-SARSAT satellites (Correct answer)
- To send distress messages on VHF Channel 16
- To activate automatic fire suppression systems
Correct answer: To transmit a distress alert with vessel identity to COSPAS-SARSAT satellites
A 406 MHz EPIRB transmits a coded distress signal including the vessel's MMSI to COSPAS-SARSAT satellites for position determination and alerting.
Question 7: Under SOLAS, how often must the batteries of a float-free EPIRB be replaced or recharged?
- Every 6 months
- Every year or when 50% of battery capacity is used
- Every 2 years or when 50% of battery capacity is used (Correct answer)
- Every 5 years
Correct answer: Every 2 years or when 50% of battery capacity is used
SOLAS requires EPIRB batteries to be replaced or recharged every 2 years, or whenever 50% of their capacity has been used.
STCW Communication Systems 2
What is the primary purpose of the NAVTEX system in maritime communications?