USCG Exam PracticeCompass variation and deviation; T-V-M-D-C
The compass rose printed on a nautical chart displays two concentric rings. What information is found at the center of the compass rose?
- A. The vessel's calculated deviation for that geographic area
- B. The gyrocompass error and annual rate of change
- ✓ The local magnetic variation and its annual rate of changeCorrect
- D. The difference between true and compass headings for the chart datum year
Why C is correct
Per the Light List source on Magnetic/Compass Rose, the center of the compass rose notes the local variation and annual change. The outer ring shows true bearings and the inner ring shows magnetic bearings. Deviation is a vessel-specific error, not a chart feature.