In theory, fly-fishing is a simple sport: Pick a body of water, choose a fly-fishing rod, select your “fly” (or bait), tie a secure knot, cast your line and, hopefully, land a fish on the other end.

Larry Fulton's hands just twisted the fishing line around a few times, he put the tangle up to his mouth and suddenly he had tied a perfect loop to attach a jig to the line. "Wait a minute. Do that ...