Navigation General · ECDIS & Electronic Aids
A gyrocompass maintains its north-seeking alignment primarily because of:
- AMagnetic attraction to the earth's poles
- BThe gyroscopic property of rigidity in space combined with the earth's rotation and gravity✓ Correct
- CElectronic compass sensors that continuously correct for magnetic variation
- DFriction in the rotor bearings that prevents precession
Explanation
A gyrocompass exploits two properties: (1) gyroscopic rigidity — the spinning rotor resists changes in orientation — and (2) precession caused by the earth's rotation and gravity. These forces are used to make the gyro settle with its spin axis aligned to true north. Unlike a magnetic compass, it is unaffected by the vessel's own magnetic field and points to true north rather than magnetic north.
Authority: Bowditch (Pub. 9), Ch. 6
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