A rock and sand structure extending from the bank of the river toward the channel is known as a（）.

A preferred-channel buoy will show a（）.

A spherical buoy may be（）.

A nun buoy will（）.

A relative bearing is always measured from（）.

From your position you observe a rotating white and green light to the north. This light is most likely（）.

Buoys are marked with reflective material to assist in their detection by searchlight. Which statement is TRUE? （）

Except for N-S courses，and E-W courses on the equator，a great circle track between two points，when compared to a rhumb line track between the same two points，will（）.

A structure，usually made of stone，or cement pilings，which extends from the bank at approximately right angles to the current is called a（）.

An orange and white buoy indicating a vessel-exclusion area will be marked with what symbol? （）