Chart Navigation & Plotting · Chart Basics — Scale
Which chart has the larger scale and shows the greater detail: a 1:20,000 harbor chart or a 1:80,000 coastal chart?
- AThe 1:20,000 chart — a smaller denominator means a larger scale and finer detail✓ Correct
- BThe 1:80,000 chart — a larger number means a larger scale
- CThey show identical detail
- DScale has no relationship to detail
Explanation
Scale is a ratio; the smaller the denominator, the larger the scale. 1:20,000 is larger scale than 1:80,000 and covers a smaller area with more detail — the harbor chart. 'Large scale, large detail; small area' is the memory aid.
Authority: Bowditch (Pub. No. 9); Chart No. 1, chart scales
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