BOATsmart! Base de connaissances du Canada 

If you are Overtaking another power-driven boat (B) from the stern (from behind) you are the give-way craft (A) and do not have the right-of-way.

You must take early and substantial action to keep well clear of the other boat by altering your speed and course. You should pass at a safe distance to the port (left) or starboard (right) side of the other boat. However, if a safe route exists, you should always attempt to pass the boat on the starboard side.