COLREG / ARPA / AIS Bridge
Rule 34(a)
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Rule 34(a) — Whistle Manoeuvring Signals
POWER-DRIVEN vessels in sight of one another use whistle signals to indicate helm actions (Rule 34(a)): (1 short, 1s) = "I am altering my course to...
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Scenario briefing
POWER-DRIVEN vessels in sight of one another use whistle signals to indicate helm actions (Rule 34(a)): (1 short, 1s) = "I am altering my course to STARBOARD"; (2 short) = "to PORT"; (3 short) = "operating ASTERN PROPULSION". You are altering course to PORT to avoid a crossing give-way situation. Which signal must you sound?
Applicable COLREG rule(s)
Rule 34(a) — 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.
Related scenarios
About SkipperCheck simulators
SkipperCheck offers two browser-based maritime training simulators:
- 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.
Both run in any modern browser, on desktop or mobile. No install, no plugins.