Pocket waters are mini-resting lies located in the midst of water unsuitable to hold fish. Search for pockets in the middle of a fast riffle or in slow shallows; likewise, a snag caked with vegetation can provide protective cover even in the shallows. A large rock in the midst of fast water cushions its flow, creating a small holding lie. These areas can hold a few fish.
Pocket-holding fish are opportunistic feeders and they must make immediate feeding decisions. A wide variety of fly patterns tied in larger sizes can be effective. Attractor patterns are also effective.
I enjoy fishing pocket water because the first cast is the most effective one. Drift boat fishing puts you into a multitude of pocket lies where fast, accurate casts produce fish.
Water temperatures play a vital role in finding fish. Swift, cold flows are just too energy consuming for fish to hold in riffles. At times of more favorable temperatures, fish spread throughout a riffle to forage.