Fly-fishing has a certain mystique. It's not uncommon for an angler equipped with a deep knowledge of aquatic insects and a perfect midair loop to stand in the cold for hours without netting a single trout.

Some say catching fish is not the ultimate goal of fly-fishing.

There is the aesthetics of casting ("performed on a four-count rhythm between 2 and 10 o'clock," as Norman MacLean puts it in "A River Runs Through It") and the thrill of hooking a 3-kg pink salmon, but for many anglers the delicate art of tying flies is a key part of fly-fishing.