What we typically do is read the posts from the day before and get a idea of the depth to o start with. Then just get close to the depth and slow way down and see if we can mark a fish. I can’t mark fish doing 30 mph, but at 5 mph I can see fish, or speed up and go another mile in any direction until I do. Also look for a pack of boats, if there is a bunch of boats in a area, we stop short or past them to see if we can mark something. I don’t like to fish in a pack, if you catch one, they will start crowding you. If most of the boats are headed west, get out a half a mile ahead of them, I don’t like trolling behind someone. If I don’t get one in say 20 minutes, I move either a bit deeper or shallower.