MPN11 - I took a different view.
I see the video as a stream of traffic heading north with the incident merchant man to the west, also heading north.
The frigate is heading south and is well placed to miss the stream of traffic, being displaced to starboard and therefore likely to pass port to port.
But she’s on a collision course with the merchant man due to her being displaced.
It seems to me that by positioning as she did the merchant man could not alter course appreciably to starboard - as that would take her into the other traffic. I am assuming (for now!) that the frigate wouldn’t alter course to starboard as she was constrained by her draft.
Not for one second saying that 17 kts is a sensible speed. It all sounds rather pedestrian but I suspect it’s above the processing power of the average surface fellow. Their brethren spent a significant portion of yesteryear trying to tip me off the deck, run me out of fuel, beat me in fog based games of hide and seek etc etc - you’ve got to watch them!😉
That’s more than enough fishheadery for one watch.