When you want to "suspend" a lure in the river's current, this simple rig often solves problems. Slide an Egg Sinker on the line and pinch on a small split shot to hold it in place. Tie a floating vibrating lure to the end of the line with a small loop knot. Cast down current, then gently take in the slack until you feel the weight of the sinker. The lure will do the rest.
One favorite place to fish this rig is near the head of a rapid. Position yourself upstream from the rapids, then inch the lure back toward the egg sinker in a series of short twitches. You can fish the entire rapids with just a few casts. No wasted fishing time.