COLREG / ARPA / AIS Bridge Rule 30(a)(i) 🔒 Course / Premium

Rule 30(a) — Anchored < 50 m

NIGHT. A stationary vessel is seen. She shows a SINGLE all-round WHITE light where it can best be seen. No sidelights, no sternlight, no red lights.

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Scenario briefing

NIGHT. A stationary vessel is seen. She shows a SINGLE all-round WHITE light where it can best be seen. No sidelights, no sternlight, no red lights. Length is less than 50 m. What is her status?

Applicable COLREG rule(s)

Rule 30(a)(i) — referenced in this scenario. Practising this scenario reinforces correct application under realistic time pressure.

📸 Night recognition — 8 aspects

The same vessel rendered every 45° of aspect — bow, starboard bow, beam, quarter, stern, port quarter, beam, bow. Use this strip to learn how the lights present from each approach angle. Click any image to view full size.

Vessel at anchor (under 50 m — single white forward) viewed head-on (bow aspect) — COLREG Rule 30(b) night-recognition diagram — Bow

Vessel at anchor (under 50 m — single white forward) viewed from her starboard bow — COLREG Rule 30(b) night-recognition diagram — STBD bow

Vessel at anchor (under 50 m — single white forward) viewed from her starboard beam — COLREG Rule 30(b) night-recognition diagram — STBD beam

Vessel at anchor (under 50 m — single white forward) viewed from her starboard quarter — COLREG Rule 30(b) night-recognition diagram — STBD qtr

Vessel at anchor (under 50 m — single white forward) viewed dead astern (stern aspect) — COLREG Rule 30(b) night-recognition diagram — Stern

Vessel at anchor (under 50 m — single white forward) viewed from her port quarter — COLREG Rule 30(b) night-recognition diagram — Port qtr

Vessel at anchor (under 50 m — single white forward) viewed from her port beam — COLREG Rule 30(b) night-recognition diagram — Port beam

Vessel at anchor (under 50 m — single white forward) viewed from her port bow — COLREG Rule 30(b) night-recognition diagram — Port bow

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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