Basic Nymph-Fishing Techniques

An angler leans into his cast on an autumn day.

Don’t ever fool yourself into thinking you’ll make your fly look like a naturally drifting nymph for more than a few feet. With the average 30-foot cast, your fly will behave exactly like a drifting natural for two or three feet, sort of like a natural for 15 feet, and completely wrong for the other 12 feet. Don’t lose any sleep over this. Just as you’ll never buy or tie a fly that looks exactly like a mayfly, you’ll never get the perfect drift. But trout aren’t very bright, and pretty close is good enough to fool them.

Fish can be amazingly fussy about the speed and depth of their prey, even if the fly pattern is right. Everything you do in nymph presentation should strive to keep your fly at a trout’s level as long as possible and at a speed that does not arouse suspicion.

With the exception of some caddis pupae, scuds, and swimming mayfly nymphs, most insects drift at the mercy of the current, with an occasional wiggle of their bodies that makes them rise in the current, followed by a period of rest where they sink or stay suspended in the water column. You can’t imitate this wiggle – forget about it. The bobbing of a strike indicator in choppy water, however, may cause your fly to rise and fall gently in the water, a benefit of strike indicators that is often overlooked.

Most of the time the trout are within a foot of the bottom where current speed is slow enough to let them maintain their position without working too hard. They will move for a fly anywhere from a few inches to a few feet, depending on water temperature, clarity, and the amount of food in the water. Most times they won’t move up more than about eight inches (or they may not be able to see a fly farther because of bubbles or turbidity in the water). It’s important to get your fly close to the bottom – but obviously not on the bottom. Besides the fact that you’ll hang up on the bottom, disturbing the water and losing lots of flies, trout never eat things drifting under them because they can’t see them. Almost none of their feeding is done by grubbing on the bottom, because they have to tip their bodies tail-up, which wastes energy. Plucking food from the drift is far more efficient.

When dry-fly fishing, drag is any pull from the line or leader that makes the fly move contrary to the current, whether it’s upstream, downstream, or across-stream. are just as critical in nymph-fly-fishing, but the fly can move slightly upstream or downstream (imitating that rising and falling motion) as long as it does not move across currents. Once you cast your fly, imagine a vertical lane from the surface to the bottom parallel to the direction of the current. As long as your fly drifts along this lane, close enough for trout lying near the bottom to see it, you should be able to tease some of them into eating your nymph.

Wet-Fly Swing

Casting a fly across the current and letting it swing below you is the least cumbersome, least scientific – and probably the least productive – way of fishing nymphs. However, it can be deadly when insects are actively hatching and you see a few scattered rises in a pool. It does not work with a strike indicator, and weight on the leader hinders its effectiveness. The fly is cast quartering upstream about 45 degrees, followed by a quick upstream mend. As the fly drifts downstream, tension is put on its drift by the line and leader because the currents at the surface are always faster than below. The line and leader begin to belly downstream, pulling the fly out of that vertical lane, sweeping it across the current faster than the natural flow.

There are ways to arrest the cross-current progress of the fly. One is to make frequent small mends in the line. Reach straight out over the water, point the rod tip at the fly, and flip a small loop of line upstream. Try not to move the line lying on the surface, nor the fly or leader, when you mend. It’s natural for a drifting nymph to rise and fall slightly in the water column, but any movement you make with your clumsy arms is way out of proportion to the distance a natural fly can move. When some species of caddisflies or swimming mayflies are hatching, purposely moving the fly with mends can draw smashing strikes, but most times it does more harm than good.

In combination with mends (or instead of mends), try following the suspected position of the fly with the rod tip, keeping as much line as possible off the water by raising the rod tip to slow a fly’s sideways skid. And notice I said the suspected position of the fly, not where the line enters the water. This nymphing technique works better with short casts; with a 50-foot cast, it’s tough to keep enough line off the water to affect the fly’s drift.

The wet-fly swing works best with an unweighted or lightly weighted fly. Of course, it is the method of choice for fishing traditional winged or soft-hackle wet flies. These flies are tied on heavy hooks with soft water-absorbent materials that sink quickly without added weight, and have lifelike mobility in the water. Traditional nymphs can be used as well. I’ve had better luck with soft, fuzzy nymphs like the Hare’s Ear or hackled nymphs like the Zug Bug than I have with stiffer, harder flies like the stonefly imitation.

The wet-fly swing works better in slow to moderate currents than it does in very fast or broken water. It’s a great way to cover the middle or tail of a large pool when you have no idea where the trout are; trying to fish a 100-foot wide pool with an indicator and split shot might wear you out before you hook a fish! In smooth water like this, use at least a 9-foot leader or preferably a twelve-footer. Your fly will sink with less hindrance because these leaders have longer tippets (thinner nylon has less resistance in the water) and you’ll be keeping the heavy fly line farther from the spooky flatwater trout.

Upstream with No Indicator

I learned to fish nymphs without the benefit of strike indicators (they have only been widely used since about 1980), and I still love to fish that way if conditions allow. Sight-fishing to spooky fish in shallow water is best done without a bulky indicator because the splash of an indicator often scares trout, but there are other places you can fish effectively without a bobber stuck onto your leader. Generally, the shallower the water and the more aggressively fish feed, the easier it is to catch them without an indicator. It’s also better where currents are relatively uniform – tricky pocket water full of swirls really screams for a strike indicator.

Direct Upstream Approach

Let’s say there’s a caddis hatch on the water, you see a few splashy rises in a fast riffle, but the fish won’t touch a dry fly. Here’s a perfect opportunity to try a weighted caddis pupa or Bead-Head. Cast straight upstream or slightly across-and-upstream, just as you would a dry. It helps if your tippet collapses a bit to get the fly below the surface before the leader begins to pull it to the surface. A great trick is to employ Joe Humphrey’s famous Tuck Cast. This cast drives the fly into the water and piles some of the leader directly over it, giving the fly added margin for sinking. To perform the Tuck Cast, stop your forward cast higher than normal right after the forward power stroke. At the same time, tip your wrist down about 30 degrees below the horizontal. If you’re doing it properly, the fly will hit the water with a splat before the line and leader.

If you are fishing directly upstream, keep the rod tip low and strip in line as the current gathers it to you. Strikes will appear to make the line jump upstream, or the leader might tighten, or a curl in the butt section of the leader might straighten. It’s not black magic as many anglers would have you believe – set the hook if the line or leader do anything that looks like they are not just drifting with the current. You can hone your nymphing technique if you can find some whitefish, chubs, shiners, or bluegills. These fish take nymphs readily and hold onto a fake insect longer than trout.

When nymph fly fishing directly upstream, try to stand in the same current lane as the water you’re fishing and don’t mend line. Mending line without an indicator on the leader makes the fly move unnaturally, no matter how carefully you mend. Everything needs to be done before the fly hits the water with either a Tuck Cast or a sloppy slack-line cast. Casting directly upstream has the disadvantage of putting line and leader directly over the trout’s head, especially if you misjudge a cast. Therefore, it works best in very fast water where the splash of a fly line hitting the water may be ignored over the noise of the riffle.

High Sticking

The biggest disadvantage of fishing directly upstream with a floating line is that the current is always faster at the surface than down below because friction with the bottom of the river slows the water’s velocity. As soon as your cast hits the water, the fly line and leader move downstream faster than the sunken fly. This is why the Tuck Cast is so effective – it both drives your fly down toward the bottom and adds some slack above the fly. The fly has a chance to sink before the line draws it downstream and up through the water column. The effect is accentuated if you’re casting to the eddy behind a rock or against the far bank and your line falls on a faster current close to you.

A more typical situation than standing in the same current lane as the fly is when you are standing in the slower, shallower water near the shore and you want to fish your nymph in deeper water closer to the center of the river. If the current you’re standing in is slower than where you want to drift your nymph, the fly line will bow upstream while the nymph drifts past, quickly forming a whiplash effect, making the fly jerk upstream. If the current you are standing in is faster, the line will tow the fly downstream. This might be attractive to a trout under certain conditions, but take my word for it – 95 percent of the time you’ll get more strikes if your fly is drifting just as fast as the current.

One solution is to keep most or all of the fly line off the water by holding the rod tip high, a method developed in Colorado known as “high-sticking”. The method works best with short casts, usually under 30 feet, and is ideally suited to fast, swirling pocket water where trout aren’t too spooky and you can get very close to them. Stand just opposite to a place where you think a trout might be feeding. Cast upstream and a little beyond this spot to allow the fly to sink to a trout’s level. How far above the fish’s position you can cast depends upon the depth of the water and the amount of weight on your fly and leader. In three feet of water with a moderate current, with a bead-head fly on your leader, cast about 10 feet upstream and two feet to the other side of its suspected position. With weight on the leader or a Tuck Cast, you can cut that lead in half.

Two-Fly Rigs

Regardless of whether you try the methods above or the indicator nymphing techniques to follow, you may want to fish with two nymphs at once. The advantages are obvious—you get to try two different patterns to see which one the fish prefer, and your flies drift at slightly different levels. Before you get too excited, though, a word of warning: Where snags are frequent, you’ll lose two flies at a time as opposed to one, and when it’s windy this arrangement is on par with a root canal. Tangles are frequent, so be patient.

The most common two-fly arrangement is to add the second fly by tying it to the bend or eye of the first fly. For instance, let’s say you’re fishing a Size 12 Hare’s Ear Nymph on a 4X tippet and want to try something smaller and in a different color. Tie a 12-inch piece of 5X tippet to the bend in you Hare’s-Ear with a clinch knot, and then tie a Size 16 Green caddis Pupa to the end of the 5X. The lower fly is typically smaller than the upper fly, and the tippet used for it is one six smaller than the main tippet.

There is a temptation to try a really large fly for the upper one and a tiny fly for the lower, but I’ve found this doesn’t work well for reasons I can’t begin to fathom. Perhaps seeing two flies of vastly different proportions does not seem natural. You’ll have better luck if you don’t vary the size of the two flies by more than two hook sizes. Often you’ll see two flies on the water at once: for instance a Size 14 caddis and Size 18 mayfly. This makes your choice easy – put on imitations of corresponding size and silhouette. If there aren’t any visible hatches, try the nymph most recommended for the stream in question and the same pattern two sizes smaller. If you are mixing and matching, take your best shot with the upper fly and use the lower one for experimentation.