The PoR in reality has rudders which can be set separately. That's how the captain we spoke to manoeuvres inside the port, to and from its berthing spot. With a button, he can switch the rudder wheel to port, starboard or both rudders. In SSExtremes, the GUI we designed doesn't really cater for this. To compensate, we added a stern thruster. Trust me, manoeuvring the PoR in Calais and Dover is really hard, even with the stern thruster, without hitting the jetty. If you hit it, you get damage.
Core Campaign Mission 6 has the trip Rdam - Calais - Dover. In the future, we'll update the bridge instruments system so it can accommodate the separate rudders. We'll take out the stern thruster.