At 22:50, at the start of Orient Star course, White Marlin will have absolved 12 NM (16 / 60 hr * 45 kn) from Dover of the 18 NM Dover to Calais CA6.
The distance between Calais entrance and CA6 is some 3 NM, and the distance separating the ships is 9 NM at this time. The distance to be run by Orient Star before the meeting is 25/45 (or 5/9th) the distance that White Marlin will have sailed.
The 9 NM are the sum of the White Marlin run plus 5/9th of the same White Marlin distance, which is the same as saying that 14/9 that distance equals the 9 NM separation.
Or that the distance for the White Marlin to sail before meeting is 9*9/14 NM or some 5.8 NM, 2 cables before the CA6 buoy, or still closer to Calais, as I imagine Orient Star needs more time to get the given speed than White Marlin.
Luc
Forgot the time : 3 NM at 25 kn is 7.2 minutes, so 22:57