I prefer to do my "trolling" at sorority houses...
If you can manage though, I like two Carolina rigs with different size sliding sinkers. 1 oz and 3 oz seems to work well for me. If the current is strong I'll go with 2oz and 4oz. That way you target the bottom and mid-column.
But what really is more effective if you can not troll two lines at one is pay attention to your fish finder and look for marks. Take notice of where you see bait balls, fish arcs, and thermoclines. These would be the factors that affect the depth I troll.