Radar Observer · Plotting — Effect of Own Maneuver
After you alter course or speed, the previously plotted relative-motion line:
- AIs no longer valid; a new relative-motion line must be plotted from fresh observations to find the new CPA✓ Correct
- BRemains valid and unchanged
- CAutomatically corrects itself
- DBecomes the target's true course
Explanation
Changing own course or speed changes the relative motion, so the old relative line and CPA no longer apply. The navigator must continue plotting to confirm the maneuver is producing the intended new CPA — a trial-maneuver function on ARPA previews this before acting.
Authority: Bowditch (Pub. No. 9), Radar Plotting
Practice the full Radar Observer bank
Free spaced-repetition quizzing across 2550 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Radar Observer questions
- Display — Motion
On a relative-motion radar display, your own ship is:
- Collision Avoidance — CPA
The closest point of approach (CPA) of a radar target is:
- Collision Avoidance — TCPA
TCPA on a radar/ARPA readout represents the:
- Controls — EBL
The electronic bearing line (EBL) on a radar is used to:
- Controls — VRM
The variable range marker (VRM) on a radar measures:
- Controls — Clutter
The anti-clutter sea (STC / sensitivity-time control) is adjusted to: