Radar Observer · Plotting — Constant Bearing
While plotting, you note another vessel's radar bearing is not changing as the range decreases. This means:
- ARisk of collision exists (the CPA is at or near zero)✓ Correct
- BThe target will pass safely astern
- CThe target is stationary
- DYour radar is mis-tuned
Explanation
Rule 7(d) states that risk of collision shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change. A steady bearing with decreasing range is the fundamental radar/visual indicator of a developing collision and calls for early action.
Authority: Navigation Rules, Rule 7(d); Bowditch
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