Nymphing is one of the most productive fly fishing methods given that trout spend the majority of their time feeding below the surface. Often the question is “what nymphing tactic do I use?” There is no clear-cut answer to this question, simply because there are times when one nymphing tactic is better than others.
In recent years, European nymphing methods have gained an almost cult-like following. This bobber-free (no strike indicator) system involves keeping line and leader off the water while using weighted flies. This reduces surface tension and allows the nymph rig to quickly gain bottom, where fish spend most of their time feeding. This is why European methods are so effective and why they are so often my go-to tactic when nymphing. However, there are times when it pays to fish higher in the water column. During these times, higher typically means just below the water’s surface with a two fly, dry-dropper combination.
Trout are masters of efficiency—they position themselves where the food is. During peak aquatic hatch and terrestrial season, trout will focus more of their effort on feeding towards or on the water’s surface, since that is where the majority of the food is. Aquatic insects including caddis, stonefly, midges and mayflies transform from bottom dwelling critters and emerge to the surface to become winged adults. Trout follow this migration, feeding at the level with the highest concentration of insects.
Dry-dropper fishing involves using a dry fly to act as a strike indicator. In other words, a higher floating/higher visibility dry fly acts like a bobber while a nymph drifts immediately below in the water column. This approach allows the angler to fish immediately at depths slightly farther below the surface. This shallow water approach to nymphing is ideal for periods when fish are looking up towards the surface to feed, especially on those days when it seems like the fish have locked into a feeding zone. The last thing you want to do is fish below actively feeding fish.
As to what dry fly pattern to use, try to match the current food source. If it’s summertime and terrestrials are in play, then try using a hi-vis chubby Chernobyl or a hi-vis foam ant pattern. For most caddis hatches, I use a beefed-up poly-wing caddis. If there are mayflies hatching, I use a beefed-up version of Barr's Vis A Dun that matches the color and size of the current hatch. But, the only time I use a dry as an indicator fly is when I feel there’s a chance of a trout feeding on the surface. If for whatever reason the trout are feeding high in the water column, but not on the surface, then I suggest using a traditional indicator, which often floats higher and requires less maintenance.
Since the purpose of using a dry-dropper rig is to fish towards the top of the water column, I normally attach the nymph to the bend of the dry fly hook using a short tippet section ranging in length from 10-24” (determined by what I perceive as the trout’s feeding level). A simple five turn clinch knot is all you need to attach the tippet to the dry fly hook. As for the nymph, keep it light, as you don’t need (or want) to fish heavy flies. Use a lightweight beadhead fly (i.e. a 3/32 bead size or smaller) or an unweighted emerger pattern—just enough weight to break the surface tension and drop several inches below the surface.
The key to nymphing isn’t always fishing deep—it’s fishing your flies at the level where trout are feeding. During the times when trout are feeding higher in the water column and are looking up, using the dry-dropper approach is an excellent choice.