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.

A weight-forward fly line is simply a long line with a thicker, denser front section called the "head." This head, because of its weight, carries the fly and pulls the rest of the long, thinner line, ...