Chart Navigation & Plotting · Compass & Course
Variation on a nautical chart is found:
- APrinted inside the compass rose, with its annual change✓ Correct
- BFrom the vessel's deviation table
- CBy measuring the angle between meridians
- DFrom the tide tables
Explanation
Variation (the angle between true and magnetic north) is printed inside the chart's compass rose along with the year and annual rate of change, so it can be updated. Deviation, by contrast, depends on the vessel and is taken from her deviation table by heading.
Authority: Chart No. 1; Bowditch, Pub. No. 9
Practice the full Chart Navigation & Plotting bank
Free spaced-repetition quizzing across 2190 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Chart Navigation & Plotting questions
- Compass & Course
When converting a true course to a compass course, westerly variation and deviation are:
- Compass & Course
True course 090°, variation 10°W, deviation 4°E. What is the compass course?
- Compass & Course
Compass deviation is caused by:
- Compass & Course
A vessel's heading is the direction:
- Chart Basics
On a Mercator chart, one nautical mile is measured using the:
- Chart Basics
The principal advantage of the Mercator projection for navigation is that: