OUPV Marine Navigation 2 — Questions and Answers
Question 1: What does a red nun buoy with even numbers indicate in the U.S. buoyage system?
- The center of a navigable channel
- The right side of a channel when returning from sea (Correct answer)
- A preferred channel to the left
- An anchorage area
Correct answer: The right side of a channel when returning from sea
Red nun buoys mark the right (starboard) side of a channel when returning from sea, following the red right returning convention.
In the U.S. Aids to Navigation System (IALA Region B), red nun buoys with even numbers mark the starboard (right) side of channels when returning from sea. The phrase red right returning is the key mnemonic.
Question 2: What is the purpose of a dayboard on a navigation aid?
- To provide lighting at night
- To identify the aid during daylight hours through its shape and color (Correct answer)
- To record tidal information
- To serve as a radar reflector
Correct answer: To identify the aid during daylight hours through its shape and color
Dayboards are colored markers mounted on fixed structures that help mariners identify aids to navigation during daylight hours.
Dayboards (or daymarks) are flat, colored shapes mounted on fixed structures (daybeacons) that identify aids to navigation during daylight. Red triangular dayboards mark the starboard side of channels, and green square dayboards mark the port side.
Question 3: What does GPS WAAS provide compared to standard GPS?
- Faster vessel speed
- Improved accuracy to approximately 3 meters or better (Correct answer)
- Radar capability
- Sonar depth readings
Correct answer: Improved accuracy to approximately 3 meters or better
WAAS (Wide Area Augmentation System) improves GPS accuracy from approximately 15 meters to about 3 meters by providing correction signals.
WAAS (Wide Area Augmentation System) is an FAA-developed enhancement for GPS that provides differential correction signals via geostationary satellites. Standard GPS accuracy is approximately 15 meters; WAAS improves this to approximately 1-3 meters.
Question 4: When navigating at night, what do two vertical red lights on a vessel indicate?
- Vessel at anchor
- Vessel not under command (Correct answer)
- Vessel engaged in fishing
- Vessel restricted in ability to maneuver
Correct answer: Vessel not under command
Two red lights in a vertical line indicate a vessel that is not under command (unable to maneuver as required by the Rules).
Under the Navigation Rules, two all-round red lights displayed vertically indicate a vessel not under command, meaning it is unable to maneuver as required by the Rules due to exceptional circumstances such as engine or steering failure.
Question 5: What is the significance of a safe water mark in the IALA buoyage system?
- It marks a dangerous wreck
- It indicates navigable water all around, typically marking a channel entrance or centerline (Correct answer)
- It marks an anchoring prohibition
- It indicates a speed restriction zone
Correct answer: It indicates navigable water all around, typically marking a channel entrance or centerline
Safe water marks indicate that there is navigable water all around the mark. They are used at channel entrances, centerlines, and mid-channel positions.
Safe water marks have red and white vertical stripes, a spherical topmark if fitted, and display a white light. They indicate that navigable water exists all around the mark, making them safe to pass on either side.
Question 6: What should an OUPV operator do when the GPS signal is lost?
- Stop the vessel and wait for signal restoration
- Revert to traditional navigation methods: compass bearings, dead reckoning, and visual piloting (Correct answer)
- Continue on the same heading indefinitely
- Call the Coast Guard for a position report
Correct answer: Revert to traditional navigation methods: compass bearings, dead reckoning, and visual piloting
When GPS is lost, a competent navigator reverts to traditional methods including compass navigation, dead reckoning, and visual piloting.
GPS loss requires immediate transition to traditional navigation methods. The operator should note the last known GPS position, begin dead reckoning, use visual bearings on identifiable landmarks, plot fixes on the paper chart, and use depth soundings to verify position.
OUPV Marine Navigation 2
What does a red nun buoy with even numbers indicate in the U.S. buoyage system?