The dry fly rig

What it's for

Trout and grayling feeding on the surface. The dry fly is the rig you reach for when you can see fish rising, or when there is a hatch of insects coming off the water and fish are taking them from the top. It works on clear rivers and on stillwaters when fish are up in the surface layer. A dry fly floats on or in the surface film and imitates an adult insect: a mayfly, a caddis, a midge, a hopper. You cast it upstream of a feeding fish and let it drift down to the fish at the speed of the current, untouched by the line. It is the most visual way to fish, because you watch the fish take the fly. On rivers it shines from late spring through summer when hatches are heaviest and fish look up.

The rig at a glance

Read from the rod end to the fly, the way it lays out on the water. The thick fly line does the casting; it is the weight you cast, not the fly. At its tip is a small permanent loop. To that you join the tapered leader, loop to loop. The tapered leader is a single length that starts thick at the butt, about two thirds the diameter of the fly line, and tapers down over about 9 ft (2.7 m) to a fine point. To the fine end you add the tippet, a level length of the thinnest line, usually 0.6 to 1.2 m, sized by an X-rating (5X for most trout dry flies, 4X for bigger flies, 6X for small flies and clear water). At the very tip is the single dry fly, tied on with an improved clinch knot. The taper is the whole point: it carries energy down from the thick line to the fine tippet so the fly turns over and lands softly, and the fine tippet lets the fly drift naturally without the heavier line dragging it.

The leader system, explained

A fly leader is not one piece of line, it is a system that gets thinner step by step from the fly line down to the fly. Understanding the three parts makes every fly rig on this site easier to build. The butt is the thick end that joins the fly line; it is stiff, about two thirds the diameter of the fly line, and it carries the energy of the cast. The taper is the middle, where the line steps down in diameter over several feet so the energy keeps flowing forward and does not collapse. The tippet is the fine, level end you tie the fly to; it is the thinnest, most flexible part, so the fly lands softly and drifts free.

A bought tapered leader gives you the butt and the taper in one knotless length; you add your own tippet to the fine end and renew it as you change flies, which saves the tapered leader from getting shorter every time you tie on. The whole system joins to the fly line loop to loop: a small loop on the fly line tip and a perfection loop in the leader butt, threaded one through the other, so you can swap leaders in seconds without cutting.

How to build it

1. Loop the leader to the fly line. Most fly lines come with a small welded loop at the tip. Tie a perfection loop in the thick butt of the tapered leader, then join the two loop to loop: pass the leader loop through the fly line loop, then pass the whole leader through the leader loop and snug it down. This gives a neat, strong join you can undo to swap leaders.
2. Add the tippet. Tie a length of tippet (0.6 to 1.2 m, sized to your fly) to the fine end of the tapered leader. Join two similar diameters with a surgeon's knot, the quickest reliable join, or a blood knot for the neatest join between two close diameters. Adding tippet here means you renew this fine end as you change flies, instead of shortening the tapered leader.
3. Tie on the dry fly. Tie the dry fly to the end of the tippet with an improved clinch knot. It is the standard, reliable knot for tying a fly to fine tippet. Pass the tippet through the eye, wrap, and seat it neatly so the fly sits straight.
4. Dress the fly and check the drift. Treat the fly with floatant so it rides on the surface, and check that the leader and tippet lie out straight, not in a heap. A leader that turns over and lays the tippet out straight is what lets the fly land softly and drift drag-free. If the tippet keeps piling up, it may be too long or too fine for the fly; shorten it or step up a size.

How to fish it

Watch the water and find a rising fish, or fish the likely lies during a hatch. Cast so the fly lands upstream of the fish and drifts down to it at the speed of the current. The aim is a drag-free drift: the fly moving exactly as a real insect would, with no pull from the line skating it across the surface. Drag is what spooks a feeding trout, and it shows as a tiny wake behind the fly. Beat it by mending the line, flicking a loop of line upstream after the cast so the current does not grab it, and by casting slack so the leader lands in soft curves that buy the fly a few feet of free drift. Lead the fish, do not line it: drop the fly above the fish, not on its head. When a fish takes, pause a beat, then lift the rod gently to set the hook. A trout takes a dry fly with a deliberate rise; do not snatch it away. On rivers, work upstream so you approach fish from behind. At first and last light, when most rivers fish best, the rises are easiest to see against the low sun.

Where this rig works

As the atlas grows, the trout, salmon and grayling waters that fish a dry fly will link to this same page. The waters lined up for it are the Bighorn River in Montana, a cold tailwater that produces fat brown and rainbow trout on hatches; Arthurs Lake in Tasmania, wild brown trout to a mayfly hatch from November to February; the Soča in Slovenia, fly-only water for native marble trout and grayling in summer; Þingvallavatn in Iceland, gin-clear water you wade for trout and char; Lake Jindabyne in the Snowy Mountains, brown, rainbow and brook trout off the shore at first and last light; and the Kenai River in Alaska, big native rainbows in autumn. Each guide will tell you when to reach for the dry fly by season, hatch and time of day.

Dry fly rig questions