Overtaking

Rule 13

Any vessel overtaking another must keep out of the way.

A vessel is overtaking when approaching from more than 22.5 degrees abaft the other vessel's beam, meaning from a sector where at night it would see only the sternlight and neither sidelight.

Important points:

if in doubt, assume you are overtaking

a later change in bearing does not convert the situation into a crossing case

the overtaking vessel remains responsible until finally past and clear

Rule 13 applies regardless of the general vessel hierarchy in Rule 18