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USCG Exam PracticeLight List, ranges, and light characteristics

A light is charted with the characteristic string 'Iso 6s' with no colour designation. What colour is this light, and why?

  1. A. Red, because red is the default colour for Isophase lights
  2. White, because white is the default light colour and is omitted from the characteristic stringCorrect
  3. C. Green, because the absence of a colour code indicates a starboard-hand aid
  4. D. The colour cannot be determined without consulting the Light List directly

Why B is correct

White is the default light colour and is omitted from the characteristic string when the light is white. Therefore, 'Iso 6s' with no colour designation indicates a white Isophase light with a 6-second period.

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A light is charted with the characteristic string 'Iso 6s' with no… — USCG Exam Practice · CaptainsGround