Narrow Channels & Traffic Separation
Where the open sea ends and ship traffic concentrates — narrow channels, separation schemes and the busiest straits in the world. Get this block wrong and a 200,000-ton container ship becomes the last thing you ever see.
Built for: skippers crossing Dover Strait, Bosphorus, Strait of Gibraltar, Singapore Strait and the Solent; STCW Officer of the Watch trainees handling commercial transits; charter skippers approaching Adriatic and Aegean port entrances; commercial deck officers preparing for re-validation.
Why this module exists
Rules 9 and 10 are where small-craft skippers most often clash — culturally and legally — with commercial shipping. A yacht skipper at the wheel of a 38-foot cruiser may believe sail-vs-power gives them right of way; in a narrow channel or TSS, that belief can be fatal. Rule 9 and Rule 10 override the give-way / stand-on logic of Rules 12–18 in their respective waters.
The simulator places you in real geography: the Western Approaches off Ushant, the eastbound lane off South Foreland, the Bosphorus turn at Yeniköy, the Tanjung Pelepas approach. AIS shows you commercial traffic at scale; the panel records whether you stayed in your lane, crossed at right angles, and yielded space when required.
The simulator scenarios
- TSS Crossing — eastbound lane of the Dover TSS, you're transiting from Calais to the Solent. Cross at right angles, do not impede a ULCC making 18 knots. Free demo scenario.
- Bosphorus Northbound — Tarabya curve, current 3 kn, ferry approaching from starboard, ship from astern (Rule 9(e) overtaking in narrow channel — you must signal whistle).
- Singapore Strait Westbound — three-target encounter, shipping density extreme, fishing vessel in inshore traffic zone.
- Solent Joining Eastbound — you're under sail, the lane is in front of you. Inshore traffic zone usage required.
- Channel Bend — limited visibility around the bend, Rule 9(f) signal (one prolonged blast) required, plus Rule 9(b) "do not impede" applied to your 12-metre yacht.
- TSS Departure — you've used the southbound lane, now leaving at termination. Show the simulator you can leave at as small an angle as practicable to the general direction of traffic.
Common mistakes
- Crossing the TSS at an oblique angle — "saving time" by cutting at 30°. Simulator marks this as a Rule 10(c) violation and shows you the radar reach you'd have on a real container ship's bridge.
- Forgetting that Rule 9 trumps sailing-vessel rights — a sailboat in a narrow channel does not have priority over a commercial ship confined to it.
- Anchoring in a narrow channel — Rule 9(g) prohibits this except in emergency.
- Fishing in the lane — Rule 10(i): vessels engaged in fishing shall not impede the passage of any vessel following a traffic lane.
- Joining the lane from the side — Rule 10(b)(ii) requires joining or leaving at the termination, or at as small an angle as practicable.
📸 Bridge-simulator scenes from this module
Each row shows one scenario: the law text + scenario name on the left, the matching simulator-rendered radar/AIS scene on the right. Captured at scenario T = 0 — the moment the encounter begins. Click any image to open full size.
Bridge-simulator scene under COLREG Rule 9(a) — Narrow channel — keep starboard. Captured from the SkipperCheck COLREG / ARPA / AIS bridge simulator.
Bridge-simulator scene under COLREG Rule 9(e) — Narrow channel — overtaking. Captured from the SkipperCheck COLREG / ARPA / AIS bridge simulator.
Bridge-simulator scene under COLREG Rule 10(c) — TSS — crossing at right angles. Captured from the SkipperCheck COLREG / ARPA / AIS bridge simulator.
Bridge-simulator scene under COLREG Rule 10(b)(ii) — TSS — joining at a shallow angle. Captured from the SkipperCheck COLREG / ARPA / AIS bridge simulator.
