USCG Exam Practice · Radar fundamentals and ARPA basics
Which radar range scales are identified as principal scales used in piloting?
- A0.25, 1.0, 2.0, and 4 nautical miles
- B0.5, 1.5, 3, and 6 nautical miles✓ correct
- C1.0, 3.0, 6.0, and 12 nautical miles
- D3, 4, 12, and 16 nautical miles
Why B is correct
Bowditch identifies 0.5, 1.5, 3, and 6 nautical miles as the principal radar range scales used in piloting. Short ranges give the best discrimination for collision avoidance; long ranges give the best landfall detection. (Bowditch Ch. 13 §1302)
Cited:Bowditch Ch. 13 §1302
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