When oily ballast has been pumped overboard，an entry must be made in the（）.

单项选择题When oil is discharged overboard，an entry is required in the（）.

A.engine rough log
B.Oil Record Book
C.Official Logbook
D.deck rough log

单项选择题When must the Master of a vessel log the position of load line marks in relation to the surface of the water in the Official Logbook?（）

A.Once a day
B.At the change of every watch
C.Only when in fresh or brackish water
D.Prior to getting underway

单项选择题When is the density of the water required to be logged in the logbook of a ship?（）

A.Any time the vessel moves from water of one density into waters of a different density
B.Prior to getting underway when the vessel is floating in fresh or brackish water
C.Only when the vessel moves from fresh water into salt water
D.The density of the water is not required to be logged in the unofficial logbook

单项选择题When are fore and aft draft readings required to be entered in the unofficial logbook of a ship? （）

A.Once a day
B.Once a week
C.Prior to getting underway
D.Only when entering waters of different density

单项选择题When an azimuth of the Sun has been taken and the deviation of the standard magnetic compass computed，the watch officer should record the results（）.

A.in the vessel's Official Logbook
B.on the compass deviation card
C.in the compass deviation log
D.on a Napier diagram