Chart Navigation & Plotting · Distance, Speed & Time
A vessel covers 9 nautical miles in 45 minutes. What is its speed?
- A10 knots
- B12 knots✓ Correct
- C15 knots
- D18 knots
Explanation
Speed = distance ÷ time. Using 60D = S × T: S = (60 × 9)/45 = 540/45 = 12 knots. Always keep time in minutes when using the 60D form.
Authority: Bowditch, Pub. No. 9 (speed-time-distance)
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