Radar Observer · Plotting — Closing Speed Head-On
Own ship makes 14 knots and a target is on a near reciprocal (head-on) course at 16 knots. The rate of closing (speed of relative motion) is about:
- A30 knots✓ Correct
- B2 knots
- C15 knots
- D224 knots
Explanation
For vessels meeting nearly head-on, the closing rate is the sum of the speeds: 14 + 16 = 30 knots. The high relative speed means little time to act — radar plotting and early, substantial action are essential.
Authority: Bowditch (Pub. No. 9), Radar Plotting
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