Normally the red and green lights would be on the vessel, not the fixed object - such as a canal (or station in ED's case). But given that we don't have these nav lights on our ships, which seems to me to be the right decision given the nature of the world in which we play, then they have to be on the fixed object. So they have to be set up in such a way that the give way rules will be effective - which are, move to the starboard (right, green) in order to keep the other vessel on your left (port, red). Travelling down the middle of a canal is the correct course generally but what hasn't been implemented in the AI (or the docking computer I suspect but I don't have one so don't really know for sure) is the give way action. The lights are reversed between the inside and the outside to mimic the lights that you would see on a vessel coming towards you and makes the give way rules work. It all works just fine if you simply remember that it is you who should give way (and this is normal at sea as well, generally speaking because it is EVERYBODY'S responsibility to avoid collisions) and move in the right direction. AND - stay out of the slot when a majorly bigger ship is already in there! Just take sensible piloting actions and all will be fine. So, it might be a little irritating that the AI won't adjust their course to give way to you, but really, are you so special that everybody should give way to you anyway? I don't think so.