COLREG 1972 · rule 10 of 38
EnglishEN

Rule 10. Traffic separation schemes

These are the sea lanes on approaches to ports and in straits. Inside them you proceed in the appropriate traffic lane in the general direction of traffic flow, keeping clear of the separation line or zone.

Part of the convention Always: clear weather and fog alike

These are the sea lanes on approaches to ports and in straits. Inside them you proceed in the appropriate traffic lane in the general direction of traffic flow, keeping clear of the separation line or zone.

  • Join and leave at the ends of the lane. From either side, do it at as small an angle as practicable to the general direction of flow.
  • Avoid crossing lanes. If you must cross, do it on a heading as nearly as practicable at right angles to the general direction of flow: you clear the lane fastest and your aspect is unmistakable.
  • Do not use an inshore traffic zone when you can safely use the lane. Exceptions: vessels under 20 m, sailing vessels, vessels engaged in fishing, and vessels going to or from a port, offshore installation or pilot station inside the zone.
  • A fishing vessel must not impede any vessel following a lane. A vessel under 20 m or a sailing vessel must not impede a power-driven vessel following a lane.
  • Avoid anchoring in the scheme or near its ends. If you are not using the scheme, keep well clear of it.
At sea it looks like this

Crossing the Dover Strait diagonally to shorten the trip is a breach. You steer 90 degrees to the flow even if the tide sets you sideways.

The rule says«…if obliged to cross a traffic lane shall do so on a heading as nearly as practicable at right angles to the general direction of traffic flow.»

Check yourself

What is an inshore traffic zone and who may use it?

The strip between the coast and a traffic separation scheme. It is used by vessels under 20 m, sailing vessels, vessels engaged in fishing, and any vessel going to or from a port, installation or pilot station inside the zone.

Rule 10 (d).

How do you cross a traffic lane correctly?

On a heading as nearly as practicable at right angles to the general direction of flow, and ideally not crossing at all.

Rule 10 (c).

How do you join and leave a traffic lane?

At the ends of the lane. From either side, at as small an angle as practicable to the direction of flow.

Rule 10 (b) (iii).

Part of the convention: Always: clear weather and fog alike