Rules of the Road · Power-Driven Vessels
A power-driven vessel 50 meters or more in length underway at night must show:
- AOne masthead light forward, sidelights, sternlight
- BTwo masthead lights (forward higher than aft), sidelights, sternlight
- CTwo masthead lights at the same height, sidelights, sternlight
- DTwo masthead lights (forward lower than aft), sidelights, sternlight✓ Correct
Explanation
Rule 23(a) requires a forward masthead light and a second masthead light abaft and higher than the forward one. This gives a distinctive profile — the farther light is always the higher one — helping observers judge the vessel's heading.
Authority: 72 COLREGS Rule 23(a)
Practice the full Rules of the Road bank
Free spaced-repetition quizzing across 2190 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Rules of the Road questions
- Power-Driven Vessels
A power-driven vessel underway and less than 50 meters in length is required to show which lights at night?
- Power-Driven Vessels
A power-driven vessel less than 7 meters in length whose maximum speed does not exceed 7 knots may, in lieu of the prescribed lights, show:
- Power-Driven Vessels
You observe a vessel at night showing two white masthead lights (forward lower), green and red sidelights, and a white sternlight. What type of vessel is it?
- Power-Driven Vessels
What is the minimum visibility range required for the masthead light of a power-driven vessel less than 12 meters in length?
- General & Definitions
72 COLREGS apply to vessels upon which waters?
- General & Definitions
Under 72 COLREGS, which statement best describes the word 'vessel'?