VTS Traffic Management and Navigation 3 — Questions and Answers
Question 1: During a vessel's transit through a VTS zone, the operator notices an unexpected current set causing the vessel to drift toward a shoal. What information should the VTS operator immediately broadcast?
- A navigational warning including the current conditions and potential hazard
- A notice to mariners to be published the following day
- A coast pilot update for future transits
- A SECURITE call on channel 16 for all traffic in the area (Correct answer)
Correct answer: A SECURITE call on channel 16 for all traffic in the area
A SECURITE call on Channel 16 is the appropriate broadcast for navigational safety information affecting vessels in the area.
Question 2: Which radar display mode is most useful for a VTS operator monitoring relative motion between vessels in a busy harbor entrance?
- True motion mode
- Relative motion mode (Correct answer)
- North-up stabilized mode
- Course-up unstabilized mode
Correct answer: Relative motion mode
Relative motion mode shows vessel movements relative to a fixed reference point, making it easier to assess potential collision risks between multiple vessels.
Question 3: A deep-draft vessel requests transit through a shoaling channel. The VTS operator's tide tables show minimum underkeel clearance will be 0.5 meters at passage time. What factor should the operator consider first?
- Whether the vessel has tug assistance
- The vessel's squat effect at the planned transit speed (Correct answer)
- The cargo type aboard the vessel
- The vessel's flag state requirements
Correct answer: The vessel's squat effect at the planned transit speed
Squat effect reduces underkeel clearance at speed and must be factored in when assessing whether a deep-draft vessel can safely transit a channel.
Question 4: A VTS operator is managing traffic during a period of reduced visibility. Which action best supports safe vessel movement?
- Suspending all vessel movements until visibility improves to 1 nautical mile
- Implementing a one-way traffic flow in the main channel and advising vessels accordingly (Correct answer)
- Increasing radar scan rate and monitoring without issuing guidance
- Requiring all vessels to anchor until conditions improve
Correct answer: Implementing a one-way traffic flow in the main channel and advising vessels accordingly
Implementing one-way traffic flow and advising vessels reduces collision risk in restricted visibility without unnecessarily halting all operations.
Question 5: Under 33 CFR Part 161, which vessels are required to participate in a VTS in US waters?
- Only vessels carrying hazardous materials
- Self-propelled vessels of 300 GT or more engaged in commercial service (Correct answer)
- All recreational vessels over 40 feet
- Foreign-flagged vessels only
Correct answer: Self-propelled vessels of 300 GT or more engaged in commercial service
Under 33 CFR Part 161, self-propelled vessels of 300 GT or more in commercial service are generally required to participate in US VTS.
Question 6: A vessel operating in a VTS zone reports a medical emergency onboard. The VTS operator's immediate priority should be to:
- Direct the vessel to anchor in the nearest designated anchorage
- Relay the medical emergency to the Coast Guard and assist in coordinating vessel movement (Correct answer)
- Broadcast a MAYDAY on behalf of the vessel
- Contact the nearest hospital directly for medical advice
Correct answer: Relay the medical emergency to the Coast Guard and assist in coordinating vessel movement
VTS operators relay medical emergencies to the Coast Guard and assist with vessel movement coordination while Coast Guard assumes responsibility for the SAR response.
Question 7: When plotting a vessel's track on a VTS chart, the operator notices the vessel is consistently making good a course 10 degrees to the left of its reported heading. This most likely indicates:
- The vessel's gyrocompass has failed
- A significant current or leeway is affecting the vessel's track (Correct answer)
- The vessel's AIS data is corrupted
- The radar is improperly aligned
Correct answer: A significant current or leeway is affecting the vessel's track
A persistent angular difference between a vessel's heading and its track made good indicates the influence of current or wind-induced leeway.
VTS Traffic Management and Navigation 3
During a vessel's transit through a VTS zone, the operator notices an unexpected current set causing the vessel to drift toward a shoal.
What information should the VTS operator immediately broadcast?