Rapala floating bibbed minnow lures are very effective for chasing large brown trout in shallow fast water situations.  They give you the flexibility of being able to steer the lure around boulders or logs to fish the likely looking pocket water where fish may be holding out of the current.  When you cast a floating minnow it floats on the surface and drifts to your preffered location, then when you retrieve it dives down into the deeper holes.  If you pause the retrive you can float it over structure and you can steer it by moving your rod tip.  This prevents snagging and allows you to thoroughly cover the water quickly and efficiently.