There is nothing more satisfying than when I'm presenting a perfectly landed dry fly and watch a trout tacking it from the surface, either supping it down or taking it with vigour. I get a real buzz every time this happens, no matter the time of year as I like to dry fly fish as much as I can if the fish are rising and taking off the surface.
You can fish a dry fly for most of the year, but the best times are at the beginning of the season especially May time when the trout are having a frenzy feeding on them. Or later in the season when the daddy longlegs are about.
Dry fly fishing uses a line and flies that float. They are joined by a fine 3 to 5 meters long leader, typically of nylon monofilament line, which is tapered so that it is nearly invisible where the fly is knotted, and the angler can replace the last meter or so of nylon as required.
Most of a trout's food is carried to it on the current, so they tend to face upstream with their attention focused into the current. Trout fishermen therefore prefer to begin downstream of the fish's suspected lie and work upstream into the current. Trout can see a wide area around them, so the angler must stay not only downstream of the fish, but also as low to the ground and as far from the bank as possible, moving upstream with stealth.
Trout tend to strike their food at current "edges", where faster- and slower-moving waters mix. Obstructions to the stream flow, such as large rocks or nearby pools, provide a "low energy" environment where fish sit and wait for food without expending much energy. Casting upstream to the edge of the slower water, the angler can see the fly land and drift slowly back downstream. The fly should land softly, as if dropped onto the water, with the leader fully extended from the fly line.
The challenge in stream fishing is to place the fly with deadly accuracy, within inches of a protective rock for instance, to mimic the behaviour of a real fly. When done properly, the fly appears to be just floating along in the current with a "perfect drift" as if not connected to the fly line. The angler must remain vigilant for the "take" in order to be ready to raise the rod tip and set the hook.
Due to rivers having faster and slower currents often running side by side, the fly can overtake or be overtaken by the line, thus disturbing the fly's drift. Mending is a technique whereby one lifts and moves the part of the line that requires re-aligning with the fly's drift, thus extending the drag free drift. The mend can be upstream or downstream depending on the currents carrying the line or fly. To be effective, any mending of the fly line should not disturb the natural drift of the fly. Learning to mend is often much easier if the angler can see the fly.
Unlike wet fly fishing, the "take" on a dry fly is visible, explosive and exciting. Right from the beginning, anglers often prefer dry fly fishing because of the relative ease of detecting a strike and the instant gratification of seeing a trout strike their fly. Nymph fishing may be more productive, but dry fly anglers can become addicted to the surface strike.
Once a fish has been caught and landed, the fly may be wet and no longer float well. Flies can sometimes be dried by "false" casting back and forth in the air. With care, a small piece of reusable absorbent towel, an amadou patch or a Chamois leather may be used. A used dry fly which refuses to float may be replaced with another similar or identical fly while the original dries out more thoroughly, rotating through a set of flies. After drying a fly may need a fresh application of water-repellent fly "dressing" liquid.
A dry fly is designed to land softly on the surface of the water without breaking it and becoming wetted. It need not be inherently buoyant. They are often oiled or treated with another water repellent. Dry flies are generally considered to be freshwater flies.
A dry fly may be of the imitation or attractor type. Imitations typically represent the adult form of an aquatic or terrestrial insect, such as the elk hair caddis, a caddisfly imitation. The small blue winged olive is another common fly, for which several imitators have been designed. A beginner may wish to begin with a fly that is easier to see, such as the Royal Wulff attractor or a mayfly imitation such as a parachute Adams. The "parachute" on the parachute Adams helps the fly to land as softly as a natural on the water and has the added benefit of making the fly very visible from the surface. Being able to see the fly easily is helpful to the beginner.