Fly Fishing Techniques, How To Fly Fish

Presentation- Fly Fishing a Hatch

a Bit of History

The first description of the concept of presentation appeared in 1676, in “The Universal Angler”, the only edition to combine Izaak Walton’s “The Complete Angler” with two additional works, written by Charles Cotton and Col. Robert Venables, respectively. It was Venables’ who penned the description of presentation, which is as applicable today as it was when first written-

“Fish take all sorts of baits most eagerly and freely, and with the least suspicion or bogling, when you PRESENT the same unto them in such order and manner, as Nature affords them, or as themselves ordinarily gather them.”

Presentation then, is where “the rubber hits the road”.  It is the application of the fly fisher’s knowledge of trout behavior and their feeding habits, one’s ability to “read the water” and understand where trout may lie, one’s knowledge of trout food sources and their imitations, and one’s casting and line management skills. It is a continuous challenge to acquire the knowledge and skills necessary to present an artificial fly naturally in every situation one may encounter. There are so many different fishing conditions and related variables, that entire books have been written about this phase of fly fishing. Hence, in “Presentation – Fly Fishing a Hatch”, I am going to limit the discussion to one situation, presentation during a hatch. I anticipate writing future articles concerning presentation in other situations.

In my view, presentation begins when one first approaches a stream, and starts to look for sections of water likely to host a hatch and draw trout to the surface to feed. Riffles and the runs below them are a good place to begin. They are the incubators and nurseries of the invertebrate foodstuffs that trout feed on. Aquatic insects lay their eggs in or over the rushing water of the riffles, where they hatch into larvae or nymphs. Because riffles are created by an upsweeping collection of rocks, the water is usually more shallow, and the rocks heavily sunned. This results in the growth of plants, algae, and plankton, providing both cover and food for the growing larvae and nymphs. When they prepare to emerge into their adult stages, they cast themselves into the drift, and are carried into the runs below the riffles. These runs are marked by foam-lines, a collection of bubbles on the water’s surface, created by aeration of the water as it passes over and through the rocks of the riffles. Such runs are the most reliable stretches of a stream to find a hatch and surface feeding trout.

Below is a picture of a stream with an easily seen foam-line. Hopefully you can find one sans fisherman!

a foam-line
a foam-line

Having spotted a likely looking run, the process of presentation continues with determining how to approach the stream without spooking the fish, and selecting a location for that all important first cast. In streams, fish position themselves looking into the current, which means that with the exception of backeddies, they are looking upstream. Therefore, in order to avoid detection, it is best to approach the stream from below the downstream end of a run. Always take notice of the angle of the sun, as trout are very wary of shadows cast over the surface of the water. Ideally, you will position yourself such that the sun will be overhead, to the side, or filtered by streamside foliage, and therefore, will neither cast your shadow over the water, nor shine brightly into your eyes, making it difficult to see your fly. But if the ideal isn’t possible, the most important sun-related factor to avoid, is casting a shadow over the water to be fished.

The next element is stealth. The clearer the water, the smaller the stream, the more important it is to approach the stream stealthily. It is important to wear clothes that blend with the streamside foliage, to move slowly, and to use streamside structures to hide your approach. It is also helpful to recall a trout’s visual field, sometimes referred to as its cone of vision, or window. A trout’s vision above the water’s surface is limited to the area immediately overhead, shaped like an inverted cone with the point resting on the trout’s head, and above a line beginning on the water’s surface at the edge of the cone, and angling outward and upward at an angle of ten degrees. To the fly fisher this means that the closer one gets to the fish, the lower one’s profile needs to be in order to remain outside the trout’s visual field, and unseen. According to J.C. Mottram, the ratio of the horizontal distance from the window to the line of visibility is 6 to 1. That is, at eighteen feet from the trout, one must remain below three feet, and at thirty feet, one must remain below five feet to remain unseen, provided the water is clear and the surface is smooth. Under less challenging circumstances, one can usually push this ratio a bit lower, that is 5 to 1, etc.

Having reached the edge of the stream, undetected, the next step is to identify the hatching bugs, at least in terms of their size, shape/form, and color. Select an artificial fly that is no larger than the bugs seen on the water, that approximates their color, and represents a vulnerable state of the bug. For an in depth discussion of fly selection, please see my February 2015 article, “Tying Flies for Better Trout Fishing“.

Next, look for rising fish, and carefully note their locations. Generally, you will want to target the fish farthest downstream, and work your way up the run, targeting each rising fish, one at a time. You will want to try and play each hooked fish downstream, rather than letting it run upstream into the unfished water, which will often spook the other fish.

Having selected the first fish to target, envision a position from which to make your first cast. The ideal position from which to cast will be a short distance downstream of the trout, outside its visual field, and require a cast of no more than 20-30 feet, angled approximately 45 degrees upstream. Water clarity and surface motion will determine how close one can get to the targeted fish. A clear and quiet surface will necessitate a longer cast to avoid detection, while the reverse will permit one to get closer for a shorter cast. While long casts may be fun and look beautiful, short casts are better for fishing, as they are usually more accurate and hook-up and landing success will be improved. Therefore, always try to cast from a spot as close to the targeted fish as possible.

The fly should land softly upon the water, above the trout’s last riseform. The picture below reveals a typical riseform, and the fly should land 2-3 feet upstream, i.e. to the left in this picture, of the outer edge of the riseform.

a riseform
a riseform

Factors that may be present and could affect your ability to reach and effectively cast from a selected position include water that is too quiet to wade in, sending ripples across the water’s surface that the trout will sense with its lateral lines, water that is too deep or fast to wade, a muddy bottom that sucks you in, structures in the stream or streamside that will interfere with your cast, a sun location that will cast your shadow over the targeted fish, and a strong wind. All of these factors should be accounted for before selecting the ideal starting position and making the first cast. Some times the ideal isn’t possible, and a next-best position must be found instead.

Below is a picture taken from the spot that I would select to start fishing this run, assuming that my first targeted fish is in the foam-line, and roughly on a line from my feet to the tip of the closest fallen tree on the opposite bank. The sun is not an issue, and there  is no structure or wind to interfere with my cast. If possible, I would wade about ten feet into the water, or otherwise cast from the bank, kneeling to lower my profile.

a foamline on the Firehole River
a foamline on the Firehole River

During a hatch, the usual presentation of a dry fly is a “dead drift”, that is, a drift that allows the fly to sit quietly on the water’s surface, and to be carried by the current to the waiting trout, just as the natural bugs are. The drift should be started 2-3 feet above the trout’s last riseform, and ideally drift downstream on a line within a few inches of the feeding trout’s position, approximated by the center of the riseform. When trout are in a feeding lie, they will rarely move more than a few inches to either side to grab a fly, natural or artificial. Hence the ‘oft cited rule that one must envision a casting target the size of a dinner plate.

If several accurate dead drifts are refused, and the targeted trout is still feeding, that is, it hasn’t been spooked, it is time to make an adjustment. One approach is to start switching flies, while another is to review each aspect of the presentation, looking for ways to make the fly’s approach more natural. I generally follow the latter approach. First, I carefully time the pattern of rises, that is, does the fish rise every thirty seconds, forty-five seconds, sixty seconds, etc., and then adjust the timing of my cast, if necessary to coincide with the next anticipated rise. Next, I try giving the fly a slight twitch as it approaches the waiting trout, to simulate a struggling, live bug. Should that fail, I then reconsider whether my tippet length and size are allowing my fly to drift naturally. The more quiet and clear the water’s surface, the longer and smaller diameter the leader and tippet will need to be. For dry fly fishing, I typically use leaders and tippets that are 12-16 feet in combined length. To determine the size or diameter of the tippet to be used, I use the general “rule of three”. I multiply the “X-factor” of the tippet times three to determine the appropriate sized fly to be used. For example, a 5X tippet multiplied times 3 is 15. This approximates the smallest fly that will float and drift naturally when attached to a 5X tippet, in this instance a #14 fly. A #16 fly would do better with a smaller tippet, size 6X. Having said that, when faced with refusals, it never hurts to extend the tippet length, and/or use a smaller diameter tippet.

When fishing a hatch, I hate to spend my time randomly changing flies. Thus, the last aspect that I will reconsider is my fly selection. Our tendency is to over-estimate the size of the natural fly, and thus fish with an artificial fly that is too large. Thus, if I am going to change flies, my first consideration is to down-size my fly. I will also consider using a different shape or form of fly that imitates a more vulnerable state of the bug, such as a spinner or cripple pattern. I rarely find it necessary to use a different colored fly than originally selected.

If despite all my efforts I am still faced with an adamant refusal on the part of the trout to take my fly, I will try to wade out to the foam-line, and carefully inspect the water’s surface for bugs. Many times the answer is that two or more hatches are taking place at the same time, and the trout are locked into a different bug than I initially detected and have been imitating. Such a discovery often reveals an easy solution to the dilemma.

When fishing a run with several rising trout, I will continue to work the first trout I selected until I have either caught it, or “put it down”, which is another way of saying that I have so bungled things that the fish is scared half to death, and is now anxiously finning on the bottom of the stream, waiting for me to leave. In either event, I will then move upstream to the next rising trout, and continue until I have fished the entire run.

As you can now appreciate, presentation is multifaceted, and every time we go fishing, we are faced with a somewhat different set of circumstances. Consequently, we must always be prepared to learn something new, and make adjustments in our presentation techniques.

Written by Al Simpson, April 2015.

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