Radar Observer · Collision Avoidance — Risk Determination
Rule 7 (risk of collision) requires that, if fitted and operational, radar be used by:
- ASwitching it off in clear weather
- BWatching only the 1.5 NM range scale
- CAcquiring every target automatically and ignoring the rest
- DLong-range scanning for early warning and radar plotting or equivalent systematic observation of detected objects✓ Correct
Explanation
Rule 7(b) requires proper use of operational radar, including long-range scanning to get early warning of risk, and radar plotting or equivalent systematic observation of detected objects. Rule 7(c) warns against assumptions on scanty information, especially scanty radar information.
Authority: Navigation Rules, Rule 7(b)
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: