Well Prien used the Eastern entrence of Scapa through the blocade ships. This is modeled in GWX. What isnt is the lack of patrols inside the Scapa. I have changed this from mission editor for myself, no patrols inside the Scapa until october 13th 1939 and novice crews in everything parked there. Remember that Prien was also surfaced during the raid. So untill Priens raid there will be the chance to try to do the same in the game. Maybe with even better results.
