A.at all times
B.in the bottom return mode
C.in the volume reverberation mode
D.only when there is no current
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A.speed being made good
B.speed through the water
C.the set of the current
D.the depth of the water
A.velocity of the current
B.bottom characteristics
C.depth of the water
D.speed over the ground
A.tree or log awash in a nearly vertical position
B.crew member who refuses to work
C.upstream end of a land wall
D.buoy that is adrift
A.high pressure system
B.low pressure system
C.high dew point
D.low dew point
A.At
B.In
C.During
D.With
最新試題
An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observer’s vessel. Which of the following is NOT a characteristic of indirect echoes?（）.
Gyrocompass repeaters reproduce the indications of the master gyrocompass. They are（）.
A Doppler log in the bottom return mode indicates the（）.
Compass error is equal to the（）.
How is variation indicated on a small-scale nautical chart?（）.
The radar component that produces the synchronizing signal and triggers the indicator sweep is which of the following?（）.
A barometer showing falling pressure indicates the approach of a（）.
A deadhead is a(n)（）.
You are using a radar in which your own ship is shown at the center，and the heading flash always points to 0°. If bearings are measured in relation to the flash，what type of bearings are produced?（）.
An electronic depth finder operates on the principle that（）.