Rules of the Road · Day Shapes — NUC
A vessel not under command displays in daytime:
- ATwo black balls in a vertical line✓ Correct
- BA single black ball
- CA black cylinder
- DA black cone, apex downward
Explanation
A vessel not under command shows two all-round red lights at night and, by day, two black balls in a vertical line, where they can best be seen.
Authority: COLREGS/Navigation Rules, Rule 27(a)
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