Overtaking
(a) Notwithstanding anything contained in the Rules of part B, sections I and II, any vessel overtaking any other shall keep out of the way of the vessel being overtaken.
Regardless of what the Rules of part B sections I and II (rules 4 to 18) say, any (PD/sailing/RAM/NUC) vessel who is overtaking any other SHALL keep clear of the other vessel.
(b) A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5˚ abaft her beam, that is in such a position with reference to the vessel she is overtaking, that at night she would be able to see only the sternlight of that vessel but neither of her sidelights.
Means overtaking vessel will be in stern light sector of the vessel being overtaken. At night she will see only the stern light first. Later on when she starts gaining, she will see sidelights. Also keep in mind that if you see white light ahead, regardless of any identification alter COURSE.
(c) When a vessel is in any doubt as to whether she is overtaking another, she shall assume that this is the case and act accordingly.
If there is any confusion in mind due to close readings, or any other reason, assume the worst and play the role of OVERTAKING vessel.
(d) Any subsequent alteration of the bearing between the two vessels shall not make the overtaking vessel a crossing vessel within the meaning of these Rules or relieve her of the duty of keeping clear of the overtaken vessel until she is finally past and clear.
There may be an alteration of bearing as the vessel starts overtaking. BUT that shall not change the situation of OVERTAKING. Once you are an Overtaking vessel, you remain so till you finally pass clear of the overtaken vessel. No double thinking.