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.

There’s a lot to love about fly-fishing. The soothing sound of the rushing river. The wildlife, both in and around the river. Spending time outside with friends and family. And, of course, the actual ...