Coast Guard Test Aids to Navigation

Question 1

What color is a port-side buoy (left side when returning from sea) in the US lateral marking system?

Accepted Answer

Red

Answer

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?

Accepted Answer

Conical (pointed top)

Answer

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?

Accepted Answer

Port side of channel when entering from sea

Answer

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?

Accepted Answer

Red and white vertical stripes

Answer

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?

Accepted Answer

Odd numbers on port side, even numbers on starboard side entering from sea

Answer

Odd-numbered buoys are on the port side and even-numbered buoys are on the starboard side when entering a channel from seaward.

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