Short Line Dry-Dropper Fishing
The dry-dropper rig is one of the most useful and versatile set ups in fly fishing. This rig, when fished correctly, can be especially effective in short drift situations like you find in rocky steep-gradient streams.
A challenge in fishing a nymph in fast pocket water is that currents are unpredictable and even swell upward at times. Fish moving with the current can take, and often drop, the nymph quickly without even budging a drifting dry fly or strike indicator. To catch more of these fish it is best to use a heavy nymph like a Tung-teaser or other heavy bead head nymph dropped 12 to 48 inches from the bend of the dry fly hook.
The length of drop depends on water depth and current speed you encounter. Use your visible, size 14-10 dry fly (I like PMX's) mostly as a depth indicator and visual aid. Cast into the top of the pocket or run, give the flies one or two seconds to sink, then lift enough line to very slightly pull the dry fly along the surface or even just up off the surface. A tight line makes sure you are in contact with the nymph and you will often simply feel the strikes or feel and see them simultaneously.
This takes practice - mostly to learn to tighten up the line fast after the cast and to figure out how fast to pull the flies. Once you get it dialed in you'll be amazed how many more fish are on the take.