When fishing summer run Steelhead it is more appropriate to present your fly above the fish rather than below the fish. Summer runs like to bite. They will chase flies down that are on the surface and/or just under the surface, given conducive water temps. So respectfully, when using a sinking tip line for Summer Runs the most applicable line is one that presents the fly at the fish's holding level or above it. In essence, if your fly is bouncing the bottom with the sinking head you have chosen for the specific run you are fishing, you are most likely "below the fish".