What Is a Fly Line in Fishing?

A fly line is an integral part of fly fishing, serving as the link between the angler and the fish. The line is made from a special material, usually a combination of braided nylon, polyethylene and PVC, that is designed to be lightweight yet strong and able to cast great distances.

It also has a coating that helps it float on the surface of the water. A good fly line should be easy to cast and have minimal memory, meaning it should lay straight on the water without curling up.

The most important purpose of a fly line is to transfer energy from your casting motion to the leader and fly at the end of your line. The energy travels down through the rod and out through the tip, then along the length of your fly line until it reaches your leader and ultimately your fly. With this energy you can achieve greater distances with your casts, allowing you to reach those hard-to-reach spots where fish are likely to be hiding.

Fly lines also come in different weights according to their intended use. Typically they range from 1-9 weight with 1 being suitable for small streams or still waters while 9 being more suitable for larger rivers or saltwater applications. The weight rating will determine how much power you need in order to cast effectively with that particular fly line.

The taper of a fly line also plays an important role in its performance. A tapered design will help with casting accuracy by reducing drag on the water’s surface so that less effort is required for each cast. Tapered lines are designed for either slow or fast actions depending on what type of action you prefer when casting.


A fly line is essential for successful fly fishing as it connects an angler with their Target species by transferring energy from their casting motion down through their rod and out through their leader and onto their bait or lure. Fly lines come in different weights depending on their intended use, as well as tapers which can help reduce drag when casting for greater accuracy.

Photo of author

Lindsay Collins