Picture this in your mind. Visualize a Carolina Rig in your mind. OK now, in your mind hold the sinker steady and move the bait. The bait can be anywhere around the sinker, in front, to either side, to the rear or on top or in any combination of places. Because the bait can be anywhere and the sinker is on the bottom is one of the reasons why the Carolina Rig is so successful in catching bass in running water.
Lets visualize running water.
Any kind of current where you fish. Yep, looking for bait to get caught in the current and come their way. Yep, the same speed as the current. To be most effective cast the Carolina Rig upstream. When the sinker lands in the water watch your line.