Overtaking, head-on and crossing situations

Two bows on a sheet can suggest an encounter while leaving legal conditions unresolved. Rules 13–15 belong to Section II: vessels are in sight of one another. Rule 13 concerns any vessel overtaking another; Rules 14 and 15 address two power-driven vessels with collision risk. Head-on or crossing must not automatically be extended to two sailing vessels or radar-only detection in fog. The illustration identifies static relationships rather than a manoeuvring sequence. Its simplified hulls describe aspect and heading, not actual velocities, distances or navigable space.

Rule 13(a) requires any overtaking vessel to keep out of the way, notwithstanding Part B Sections I and II. It prevents first choosing a more convenient rule based solely on propulsion type. Overtaking comes from more than 22.5 degrees abaft the overtaken vessel’s beam, corresponding at night to seeing only its sternlight, not its sidelights. The angle references the overtaken vessel rather than our own bow or a fixed compass heading. The sector illustration therefore places that vessel at the centre and identifies its beam and stern.