Head-on, Crossing & Overtaking

Rule 13 — Overtaking

A vessel coming up on another from a direction more than 22.5° abaft her beam is overtaking and shall keep out of the way of the vessel being overtaken.

Overtaking overrides all other steering rules. Any subsequent change of bearing does not make the overtaking vessel a crossing vessel — the duty persists until finally past and clear.

Rule 14 — Head-on

When two power-driven vessels meet on reciprocal or nearly reciprocal courses so as to involve risk of collision, each shall alter course to starboard and pass port to port.

If in doubt whether such a situation exists, assume it does and act accordingly.

Rule 15 — Crossing

When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if circumstances admit, avoid crossing ahead of the other vessel.

Rules 16 & 17 — Give-way and stand-on

Rule 16: the give-way vessel shall take early and substantial action to keep well clear.

Rule 17(a)(i): the stand-on vessel shall keep her course and speed.

Rule 17(a)(ii): she may take action by her manoeuvre alone as soon as it becomes apparent that the give-way vessel is not taking appropriate action.

Rule 17(b): when collision cannot be avoided by the give-way vessel's action alone, the stand-on vessel shall take such action as will best aid to avoid collision.

Rule 17(c): a power-driven stand-on vessel taking action in a crossing situation shall, if circumstances admit, not alter course to port for a vessel on her own port side.