Coast Guard Test Aids to Navigation 1 — Questions and Answers
Question 1: What color is a port-side buoy (left side when returning from sea) in the US lateral marking system?
- Red (Correct answer)
- Green
- White
- Yellow
Correct answer: Red
In the US lateral system, red buoys mark the port side when returning from sea, following the 'Red Right Returning' rule.
Question 2: What shape is a nun buoy?
- Conical (pointed top) (Correct answer)
- Cylindrical (flat top)
- Spherical
- Diamond-shaped
Correct answer: Conical (pointed top)
Nun buoys have a conical, pointed top and are typically red, marking the starboard side of a channel when departing.
Question 3: What does a flashing green light on a buoy indicate?
- Port side of channel when entering from sea (Correct answer)
- Starboard side of channel when entering from sea
- Danger area
- Safe water mark
Correct answer: Port side of channel when entering from sea
A flashing green light marks the port side of a channel when entering from seaward, corresponding to odd-numbered buoys.
Question 4: What does a safe water mark (fairway buoy) look like?
- Red and white vertical stripes (Correct answer)
- Black and red horizontal bands
- Yellow with an X
- Green and white stripes
Correct answer: Red and white vertical stripes
Safe water marks have red and white vertical stripes and indicate navigable water on all sides, typically placed at channel entrances.
Question 5: What is the significance of the number on a lateral buoy?
- Odd numbers on port side, even numbers on starboard side entering from sea (Correct answer)
- Even numbers on port side, odd numbers on starboard side entering from sea
- Numbers indicate water depth
- Numbers indicate distance from shore
Correct answer: Odd numbers on port side, even numbers on starboard side entering from sea
Odd-numbered buoys are on the port side and even-numbered buoys are on the starboard side when entering a channel from seaward.
Question 6: What does a yellow buoy primarily indicate?
- Special purpose or caution area (Correct answer)
- Safe water mark
- Isolated danger
- Port side of channel
Correct answer: Special purpose or caution area
Yellow buoys mark special-purpose areas such as anchorages, fish net areas, or military exercise zones, and do not indicate channel sides.
Coast Guard Test Aids to Navigation 1
What color is a port-side buoy (left side when returning from sea) in the US lateral marking system?