Going to have to watch the film now to see if they remove the radar from the pilot boat's spreaders post production.
I suspect someone just forgot.
They had removed the radar from the Kathleen and May (left side of the Gloucester docks shot). It was being put back yesterday.
Update:
after checking more shots, the radars on the Kathleen and May, the Lady of Avanel, the Excelsior (LT472), the pilot cutter and the main star (Wonder/Earl of Pembroke) were all present during filming. The radar on the Earl of Pembroke was painted black, and the rader on the Excelsior was covered in canvas.
If you want to check, the other radars were located as follows
Kathleen and May: port end of mizzen mast speader
Lady of Avanel: On a separate pole a few feet the starboard side of the main mast (rear)
Excelsior: base of main topmast
Earl of Pembroke: at the base of the mizzen topmast
The Irene doesn't appear to have a radar.