pocket water
A stretch of river broken by numerous boulders and obstructions, creating many small pockets of slower water — miniature lies — in front of, behind, and between the rocks. Each pocket may hold a fish. Fishing pocket water is methodical, close-range work: you move from pocket to pocket, covering each one before stepping upstream to the next.
Etymology
Angling terminology — the slow water behind each boulder forms a "pocket" in the faster current.
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