单项选择题
A.Remove deviation on the intercardinal headings B.Remove deviation on the cardinal compass headings C.Remove heeling error D.Compensate for induced magnetism in vertical soft iron
A.nonmagnetic B.weatherproof C.corrosion resistant D.capable of being permanently affixed to the vessel
A.Comparing the gyro azimuth of a celestial body with the computed azimuth of the body B.Comparing the gyro heading with the magnetic compass heading C.Determining from the chart the course made good between celestial fixes D.It cannot be determined accurately at sea due to drift of unknown currents