VTS Equipment and Technology 3 — Questions and Answers
Question 1: What is the standard VHF working channel used by U.S. Coast Guard VTS for port operations communications?
- Channel 16
- Channel 13
- Channel 22A
- Channel 14 (Correct answer)
Correct answer: Channel 14
VTS working channels vary by port, but Channel 14 is commonly designated as a VTS working channel in many U.S. ports, while 16 is the distress/calling channel.
Question 2: An Electronic Chart Display and Information System (ECDIS) in a VTS center uses which type of chart data as its primary format?
- Raster Navigational Charts (RNC)
- Electronic Navigational Charts (ENC) in S-57 format (Correct answer)
- PDF-converted paper charts
- CAD-based harbor schematics
Correct answer: Electronic Navigational Charts (ENC) in S-57 format
ENCs in IHO S-57 format are the official vector chart format used by ECDIS, providing object-based data that supports automated alerts and overlays.
Question 3: In VTS operations, what does the term 'ARPA' refer to?
- Automatic Radar Plotting Aid — a system that tracks targets and calculates CPA/TCPA (Correct answer)
- Advanced Radio Position Antenna
- Automated Radar Port Authority system
- Acoustic Range and Position Apparatus
Correct answer: Automatic Radar Plotting Aid — a system that tracks targets and calculates CPA/TCPA
ARPA (Automatic Radar Plotting Aid) automatically tracks radar targets and calculates closest point of approach (CPA) and time to CPA (TCPA).
Question 4: A VTS operator's AIS display shows a vessel with navigational status '1'. What does this indicate?
- Under way using engine
- At anchor (Correct answer)
- Not under command
- Engaged in fishing
Correct answer: At anchor
AIS navigational status code '1' means 'at anchor,' while '0' means under way using engine.
Question 5: What is the main purpose of a Vessel Traffic Service's CCTV system compared to its radar system?
- CCTV provides longer detection range than radar
- CCTV allows visual identification and monitoring of vessels and waterway conditions (Correct answer)
- CCTV is used to track vessel speed more accurately than radar
- CCTV replaces radar in fog conditions
Correct answer: CCTV allows visual identification and monitoring of vessels and waterway conditions
CCTV provides visual confirmation and situational awareness that radar cannot, including identifying vessel types, reading hull markings, and monitoring dock areas.
Question 6: What does 'MMSI' stand for and what is its primary function in VTS communications?
- Maritime Mobile Service Identity — a unique 9-digit number identifying a vessel's radio station (Correct answer)
- Marine Management System Interface — software linking VHF and radar
- Mandatory Marine Safety Inspection — a vessel certification number
- Multi-Modal Signal Integrator — hardware combining radar and AIS
Correct answer: Maritime Mobile Service Identity — a unique 9-digit number identifying a vessel's radio station
MMSI (Maritime Mobile Service Identity) is a unique 9-digit number assigned to each vessel's radio station, used for DSC calls and AIS identification.
Question 7: In VTS radar operations, what is the purpose of the 'guard zone' or 'alarm zone' feature?
- To restrict radar display to a predefined geographic area
- To automatically alert the operator when a radar target enters a defined area (Correct answer)
- To block radar transmissions in restricted airspace
- To mark hazardous shoal areas on the display
Correct answer: To automatically alert the operator when a radar target enters a defined area
A guard zone triggers an audible or visual alarm whenever a tracked radar target enters a user-defined ring or sector, helping operators monitor critical areas.
VTS Equipment and Technology 3
What is the standard VHF working channel used by U.S.
Coast Guard VTS for port operations communications?