Fugit irreparabile tempus... I had a closer look at the "Pilot Card and Wheelhouse poster", and saw that the sea trials happened in October 2001, more than enough time since then to improve rudders or anything else more than one time. I doubt Fincantieri could have made such a mistake, but there is also question of (absent) stern thrusters on the poster, raising of course some doubts about its validity. Apparently, PoBruges and PoR underwent important repairs (or modifications?) to their rudders during maintenance works (http://www.shipdock.nl/downloads/files/Seaports%20Magazine2008.pdf) at Amsterdam's Shipdock.
Also, the wheelhouse poster data print is composite, some trials being of PoH and turning circles of PoR; or it could be that the poster wasn't checked by Fincantieri or RINA. (Impossible).
There are surely reasons for having changed the spade rudders to flapped, high lift rudders. The turning circle diameters were (as well at MCR as at full harbour speeds) around 1.8 Lbp at 45 degrees rudder angle, very small circles, with a high speed loss. But if it indicates already good manoeuvring characteristics, it is less significant at near to zero speed, when berthing, where flapped rudders at high angles are at their best.
So, to answer Nathan's question, he could next time try to check if the poster is still valid, and find some more RoT data when PoR turns "on the spot" when leaving her berth in the Beneluxhaven. Some pictures with timestamps, or a video record, would be highly interesting.
Anyway, many thanks for the interesting info.
Regards,
Luc