“As It Happens: Classic Button Hook”
Eddies form when water hits a hard structure and a deflective seam or hard corner occurs. Sometimes they’re subtle, other times they’re quite pronounced as this one is. You really have to observe the directionality of stream flow, depth, and embedded structure to understand where in the back-eddy a trout will hold. In this case, this nice rainbow trout was cruising all over because it was peak of summer, water conditions prime, the food courses strong, and this was a vibrant fish on the prowl.