Something interesting I noticed last night

[AlanSmithee]

Originally Posted by trenken

Then I loaded up my save, and that same enemy popped up in the same spot.

That's the campaign behaving as it should. If you were to reload the save again, the ship would appear again - because the save is keeping a record of the locations of all the ships in the ocean at that time. As far as I know, the campaign randomly generates ships which travel until they arrive at their destination. It isn't simply randomly generating ships within your sensor range. The ship you saw is likely mid-cruise, and during this patrol will be there, whether you see it or not. Next patrol, however, the campaign may not randomly generate a ship which crosses that location.