November 07, 2022
Editor's note: Flyfisherman.com will periodically be posting articles written and published before the Internet, from the Fly Fisherman magazine print archives. The wit and wisdom from legendary fly-fishing writers like Ernest Schwiebert, Gary LaFontaine, Lefty Kreh, Robert Traver, Gary Borger, Joan & Lee Wulff, Vince Marinaro, Doug Swisher & Carl Richards, Nick Lyons, and many more deserve a second life. These articles are reprinted here exactly as published in their day and may contain information, philosophies, or language that reveals a different time and age. This should be used for historical purposes only.
This article originally appeared in the May 1987 issue of Fly Fisherman magazine. Click here for a PDF of the print version of "Insights on Sight Nymphing."
Casting to visible fish, or sight fishing, is one of the most challenging forms of trout fishing. The thrill of presenting a fly to a fish that can be seen actively feeding is special, but success at the sight-fishing game requires use of the right tactics.
First, let's look at our quarry. If a feeding trout is not cruising, it will be feeding to the right or left. I must determine that before I make a cast. A trout usually lies where water velocity changes, and the current bringing the bulk of its food will either be to the fish's right or left. The greatest portion of food may be falling off the bank, thus the trout will work to that side, right or left. Underwater weed growth such as watercress and elodea harbors cress bugs, shrimp and nymphs. If the weed growth is next to the bank, the fish will feed to that side, or if the major currents are adjacent to the growth, the fish will position itself to feed on food dislodged from the weed growth. It may also move directly to the weed growth to dislodge and eat the food.
The same fish may change its location. It may have been feeding to one side, say to the left. Let's assume that you're about to cast and the fish moves, relocates and then feeds to the right because the currents bringing its food changed. As the trout moves, watch it. Wait until you see on which side the fish feeds and then make your cast.
Use the sun on your approach. If the sun is directly in the trout's eye, from over your shoulder, the fish can't see on that side. (Trout have no eyelids, eyelashes, eyebrows or polarized sunglasses. The fisherman has all of these aids and still can't see directly into the sun.) The position of the sun determines to which side the trout will feed. If it is blinded by the sun on one side, it must feed on the other.
When you've determined to which side the trout is feeding, time your cast during those instants when the trout is not turning, lifting or chasing but has undivided attention for your nymph. And don't cast too far above the trout: It gives the fish too much time to examine the fly, particularly in slow-moving water. Also, if your nymph is heavily weighted, it will sink below the trout's field of vision before it drifts to the fish. The speeds of the currents dictate how far above the fish you should cast. Speeding currents and velocity changes lift and drop for drifting naturals, and such fast-drifting nymphs are moving targets for trout, requiring quick take/no-take decisions. Trout that have been fished over can be lightning fast when taking and rejecting food, sometimes ejecting an imitation from their mouths instantaneously.
The fish give basic cues that can help you to strike. One of them is the movement of the trout to the nymph–when a trout nosedives for a nymph, it usually turns at the instant it picks up the nymph. When a trout turns, it has probably picked up your nymph–strike by lifting your rod tip! The flash of a trout's flank as it turns also signals your time to strike. Other trout movements that indicate times to strike include: The fish moves off to the side, lifts, or increases its tail movements when moving to the nymph. The opening of a trout's mouth as it moves in the direction of your nymph is also a cue to strike. And remember: Trout don't grab, they inhale. You must give the trout time to inhale the nymph when its mouth opens. You can strike too swiftly. With experience, you'll determine the correct timing.
Not only must you know the side to which the fish is working, you must judge the depth at which he is working. Is he staying on the bottom or lifting off the bottom to take? To get your nymph to the trout as naturally possible, the amount of weight in the fly and the length of the tippet you use should be tailored to the trout's feeding behavior and the depth and speed of the water in which he is feeding. Often you'll have to adjust (lengthen or shorten) the intermediate sections of your leader to get the right (natural) drift. This will take practice and experience in reading water types, but tailoring your leader to match water conditions is the key to successful nymphing.
For a bottom-feeding fish in deeper water, you may have to lengthen your tippet, go to a smaller tippet diameter, add a heavier nymph, or add weight to the tippet. The deeper the required ride of the fly to reach the fish at its feeding depth, the closer you must slide the weight to the nymph. If you want the fly to rise, go to a lighter-weight nymph and slide the weight farther away from the fly. If the fish is lifting, tie on a lightweight nymph that sinks slowly in the short distance it will travel, or use an unweighted pattern for a natural drift, just under the surface or in the surface film. You must be flexible and innovative in your presentations, tailoring them to trout behavior and water conditions.
If a trout refuses your fly, go to a smaller fly, change the pattern, or both. A smaller tippet diameter can make the difference–you need no less than 6X (.005") for the most sophisticated feeder in the clearest water.
And consider this–a refusal may be the result of an unnatural drift, not your choice of nymph. Improper tippet length and poor leader construction may have caused the unnatural drift. The natural, no-dragging drift of a nymph is just as important to fooling trout as the drag-free floating dry fly.
Let me illustrate this with an anecdote. One summer morning, while fishing a low, clear spring tributary to a larger limestone stream, as I slowly worked my way upstream, I spotted a trout silhouetted against the white sand and gravel of the stream bottom between patches of elodea. The casting approach with the nymph was like fishing a dry fly–short forward stroke, check the cast high, drop the elbow and then the rod tip. The casting stroke was short. The trout saw the nymph on my first and second cast but did not take. I won't stay with a trout that doesn't take when I've made a good cast and got a good drift. I'll look for another since each cast after that first one reduces my chances of a take. If I have a nymph with which I'm moving fish, I'll work it over as many trout as possible and I'll catch twice as many fish by not wasting time on any single trout.
A trout surfaced ahead. Had it not surfaced, I would not have seen it–the fish blended perfectly with the underwater weed growth. I threw some slack into the leader to change the depth and get a natural drift. My leader was stiff mono except for the last two feet of soft tippet material. The line straightened, even most of the leader straightened, but not the tippet, and I had control of line and leader from rod tip to nymph. The trout moved over. I tightened, lifting the rod tip sharply to hook and land a scrappy foot-long brown trout.
Checking the cast and changing levels gave me drift time–the cast and the leader complimented each other. A leader that is too long (11 feet or more) is too tough to handle when sight fishing–you have neither leader control nor accuracy.
The Flexible Approach
There are times when an upstream approach is impractical, and sometimes impossible. When downstream nymphing, the distance the nymph must drift, the depth and speed of the current, and the sink-rate of the nymph are all things you must consider to get a natural drift at the fish's feeding level.
The positive aspect of downstream nymphing is that the nymph, not the leader, drifts to the fish first: You don't line the fish when casting unless you make a bad cast.
Check the cast high with the downstream approach: Stop the rod tip high, pull it back, and then drop the elbow of your casting arm–this forms extra slack line and leader for an extended downstream drift.
Too much weight in the nymph or on the leader prevents a natural drift–the nymph can hang on the bottom and trout will not see it, or they will lose it. If the nymph becomes covered with weed growth or algae, a trout won't touch it.
For an off-the-bank approach, consider a low profile approach–crouch to get as close to the fish as possible before you make a cast. A close approach improves casting accuracy and line control, and when fishing close, there are fewer currents to work around for a natural drift. Water clarity and fishing pressure dictate how close you can get.
The tuck cast is valuable in getting a nymph on bottom as quickly and as naturally as possible. To execute the tuck cast wait until you feel the pull of the weighted nymph and additional weight on the leader during the backcast. Then drift the rod forward until you see your rod hand out of the corner of your eye. With a sharp hand-squeezing action, push the thumb of your casting hand forward and slightly back and up on the forward casting stroke. This drives the nymph downward at the end of the cast. The nymph tucks under the line before it lands, giving it time to reach bottom and begin a dead drift before the currents pick up the slack line on the water and induce drag. At this point elevate the rod tip, pick up the slack line, and strip or hand-twist retrieve (depending on the speed of the current) until you feel the nymph on bottom. Remember that on most casting approaches the rod tip leads the nymph through the drift. With line control and your nymph on bottom, your percentage of hookups increases.
There are other casting techniques–the "down and upper" and the "rolling tuck"–that create bottom-rolling presentations. Space precludes explaining them here, but I show them in my book Trout Tactics, (Stackpole Books, 1981) and in my video: Master Nymphing Techniques, (1986, available from Orvis and Cortland Line Company).
One aspect of nymphing that I developed back in the 1950s and have advocated for years is the monofilament technique. The fly line is all monofilament. Its diameter is smaller than that of a traditional fly line, thus allowing the line and fly to sink faster. You're using a nymph of your choice and the casting technique is the same. It's still fly fishing and your fly is on bottom instantly. Conventional fly lines (even 2- or 3- weight lines) belly and create drag. You don't have nearly the line control or sensitivity as you do when using monofilament.
The monofilament system is also deadly for fishing to salmon and steelhead where you can observe the fish in fast, deep runs. A problem in this fishing is that your nymph, in a normal presentation with a fly line, isn't in front of the fish long enough. For whatever the reason a spawning Chinook or coho strikes, the longer the fly is in front of the fish on a drift the greater the chance you have for a take.
Weight adjustment is vitally important. Several years ago as he was fishing for steelhead in a New York stream, a friend stepped into a spot that I had just fished unsuccessfully and hooked three heavy fish, landing two. He used the same technique I used, except that he also used three heavy split-shot that helped him roll his fly slowly along bottom. Although I used both a longer leader and a longer tippet with a smaller diameter, I didn't have enough weight to do the job. Although it reached bottom, my fly moved too fast. In that cold water the steelhead failed to react to it.
Using the right weight and the right leader construction, you can give your nymphs as much time on bottom (drifting naturally) as possible. It's the secret of nymphing.
Leader construction is also important in nymphing deep water. Fishing a large-diameter leader that's too short causes the nymph to be pulled off bottom. The pull of currents on the fly line causes the line to belly to the leader. Too much weight and you hang the sinkers on bottom. I constantly adjust my weight and tippet length for the depth and water speed. The new leader materials are strong for their diameters. (Some tippet material of eight-pound test measures .008" (3X) and ten-pound test measures .009" (2X).) Fishermen now have the advantage of small-diameter tippets that can take the strain of heavy fish and (thanks to the narrow monofilament diameter) they can use less weight for a slow bottom-roll presentation. Longer, finer tippets also provide a more natural drift.
When sight-nymphing in deep water, you can't avoid some slack from rod tip to nymph. Even when you feel the roll of the weight and nymph on bottom, you still may not be in direct touch with the fly. The deeper the water and the faster the currents, the more slack, even when you are trying your best to maintain line control.
Understanding that there is slack from rod tip to fly can help you hook fish you might ordinarily miss. The movement of a fish, even if it is not near your fly, may signal a take. That extra slack creates a time lapse between the movement of the fish and your setting of the hook. I've often hooked fish in anticipation of a trout's movement. It becomes instinctive.
You can minimize the slack. Use a line of 15- or 20- pound Cortland flat monofilament and taper the leader off the mono with a tippet diameter that is as small, yet as strong, as you can get away with. This gives your fly the time needed on bottom for the fish to see it. It also gives you the line control you need to hook the trout. When describing native trout, trout that have been pounded–the survivors–it's a sure bet that if you wave a fly rod around, they'll scram. Hatchery trout that are heavily fished over may or may not spook, but the more visible you are the less attentive they are to your offerings. A rule of thumb is: The less visible you are the better your chances. Work on a low profile in the stream and out. If necessary, drop down in the water on both knees for a lower profile.
Finally, remember what you can of this material, and then go fishing. I can give you shortcuts, but only time onstream can perfect your game.
Joe Humphreys is Penn State University's angling professor.