I have caught fish in all directions and I have gone dry in all directions. I first prioritize the lines cooperating, then focus on finding the right speed. Often times you must adjust GPS speed (SOG) to account for current. I have a paddle wheel speedometer as well that helps me determine that. But that is just surface current. I'm anxious to get a fish hawk connected so I can see what the speed of my tackle is at the depth of the fish. Perhaps I'm over thinking it.
Good Luck!