单项选择题
A.vessel's geographic position B.vessel's heading C.earth's magnetic field D.influence of the magnetic materials of the vessel
Compass error is equal to the（）.A.deviation minus varia...
单项选择题Compass error is equal to the（）.
A.deviation minus variation B.variation plus compass course C.combined variation and deviation D.difference between true and magnetic heading
Compass deviation is caused by（）.A.magnetism from the e...
单项选择题Compass deviation is caused by（）.
A.magnetism from the earth's magnetic field B.misalignment of the compass C.magnetism within the vessel D.a dirty compass housing
Before a magnetic compass is adjusted certain corrector...
单项选择题Before a magnetic compass is adjusted certain correctors must be checked to ensure that they are free of permanent magnetism. These correctors are the（）.
A.fore-and-aft and athwartships magnets B.dip needle and heeling magnet C.heeling magnet and Flinders bar D.Flinders bar and quadrantal spheres
