Transport Publication - TP 10038 E (2003)
Overtaking another vessel
A vessel is overtaking another when it is coming up with another vessel, from a direction more than 22.5 degrees abaft its beam. The overtaking vessel must keep clear of the stand-on vessel. The stand-on vessel must maintain its course and speed until the overtaking vessel is finally past and clear.
Any vessel overtaking another must keep clear of the stand-on vessel.