RV — Target on Port Bow (Rule 19(d)(i))
Fog. A target is detected 030 on the port bow (forward of the beam), closing with significant risk of collision.
Scenario briefing
Fog. A target is detected 030° on the port bow (forward of the beam), closing with significant risk of collision. Rule 19(d)(i): avoid an alteration of course to PORT for a vessel forward of the beam. Manoeuvre to open CPA to 1 NM.
Applicable COLREG rule(s)
📸 Bridge simulator scene
Captured directly from the SkipperCheck COLREG bridge simulator at scenario T = 0 — the moment the encounter begins.
Key teaching points
- Rule 19(d)(i): for a target forward of the beam (port OR starboard bow), do NOT alter to PORT.
- Acceptable actions: starboard alteration that opens CPA, or speed reduction, or both.
- A 30°+ starboard alteration draws the target across your bow toward your port side, where she will pass safely astern.
- Sound signals: in fog, you should be sounding one prolonged blast every ≤2 minutes (Rule 35(a)).
Common mistakes to avoid
- Port alteration "to give her room on my starboard side". Rule 19(d)(i) forbids this and the geometry tends to fail.
- A small starboard nudge that doesn't open CPA enough — fog reduces visual confirmation, so the alteration must be readable on radar.
Why it matters
Exam relevance
Port-bow targets in fog are a frequent variation of the Rule 19 oral question in Yachtmaster Offshore and STCW OOW exams.
Related scenarios
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.
- VHF SRC Radio Simulator — 15 scenarios: voice Mayday, DSC distress, Mayday Relay, Pan-Pan, Sécurité, routine.
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