COLREG / ARPA / AIS Bridge Rule 23(d) 🔒 Course / Premium

Rule 23(d) — PDV < 7 m AND < 7 kn

NIGHT. A very small power-driven vessel is observed. Her length is less than 7 m and her maximum speed does not exceed 7 kn.

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Scenario briefing

NIGHT. A very small power-driven vessel is observed. Her length is less than 7 m and her maximum speed does not exceed 7 kn. She exhibits ONE all-round WHITE light and, if practicable, sidelights. No masthead light, no separate sternlight. What allowance permits this reduced lighting?

Applicable COLREG rule(s)

Rule 23(d) — referenced in this scenario. Practising this scenario reinforces correct application under realistic time pressure.

Why it matters

COLREG knowledge is the foundation of safe ship handling. Most maritime collisions happen because watchkeepers either misidentified the situation, applied the wrong rule, or acted too late. This scenario lets you train pattern recognition + correct response under time pressure — the exact skill the rules are designed to support. RYA, Yachtmaster, STCW and most national exams expect you to apply COLREGs reflexively, not just recite them.

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About SkipperCheck simulators

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ARPA · AIS · COLREG Bridge Simulator — 54 scenarios covering Rules 2, 5–10, 12–19, 23–30, 34 and 35.
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