Forty years ago, when I first began flyfishing for trout, I was taught to always cast dry flies upstream. It was, I understood, a rule that had evolved from ironclad British traditions.
Positioning yourself below a rising fish, dropping a dry fly a few feet above him, and allowing the fly to float drag-free down to him remains a good way to fool trout. But over the years, I have learned on occasion to turn the tables on trout by fishing dry flies downstream.
Fishing a dry fly downstream still requires careful stalking and long-distance casting. That’s because trout face upstream-in your direction-and they’ll spook if they notice any movement, flash, or shadow.
Use a reach cast to present the fly precisely and to get a drag-free drift from upstream. Creep into a position above and a bit to the side of the fish. Measure the distance of the cast by false-casting to the side of the trout. If you false-cast over the fish, the line could spook him. When you’ve got enough line in the air for your fly to float 2 feet or so past the fish, cast directly toward him. As your line straightens-but before it lands on the water-bring the rod back to make the fly drop a few feet upstream of the fish. Then point the rod downstream at the fish; you should have plenty of slack in the line to give you a drag-free float. You can extend a downstream float by stripping loose line off the reel and shaking it out of the rod.
If the fish refuses the fly, let it drift well past him, then steer it away from his lie. Now when you begin to cast again, your line will be out of his vision and you won’t spook him.
When a trout refuses an absolutely natural drift, the downstream cast enables you to tighten your line and give the fly a tiny twitch as it enters the trout’s window, imitating the struggle of a living insect. This trick is impossible to execute when casting upstream.
Skittering a bushy dry fly down and across the currents on a tight line is a good way to imitate egg-laying caddisflies and fluttering mayflies. This is also an effective tactic for teasing up trout when they’re not actively feeding off the surface.
When a trout takes your fly, don’t set the hook instantly. Force yourself to pause long enough to give the fish time to close its mouth and turn away. Then simply raise your rod.
If the stream is narrow and brush-lined, or when the trout are lying in glassy shallow water close to the banks, I still prefer the upstream approach. But whenever the location of a rising trout and the configuration of the stream allows me to get into a position across and upstream from it, that’s what I do.
There’s only one rule: Stand in the place that gives you the best chance to fool a trout.