We all know that trout feed more than 80% below the surface.
Dry-fishing is often for pleasure, even if sometimes it's the technique that will catch a lot of fish when the trout are settled.
The rest of the time, they feed between two waters or near the bottom and pupate. Nymph fishing with NAF line is therefore often formidable if practised correctly.
Water reading
Reading the water is essential for both dry and nymph fishing. Dry fishing allows you to understand how a fly drifts on the skin of the water, to understand the current veins. This provides a wealth of information for underwater fishing.
This is a very good school, and starting directly with a nymph is not always a good idea. Because the quality of the drift depends on the choice of where to place the fly(s) and, of course, the weighting. If the drift isn't good underwater, the fish won't take your flies. And dredging also exists underwater!
Experience gives the angler a sense of the water. This may be innate, but it is often acquired through experience. The more you fish, the more you understand how trout behave.
Knowing how to read a river and find where the trout will be posted according to season, flow and water temperature takes time.
Trout position themselves according to their metabolism. The colder the water, the more sheltered they will be from strong currents, to limit their loss of energy.
So, as the season progresses, the flow decreases and the water temperature rises. The trout will therefore move into the stronger currents. They will be more mobile and able to move to feed.
Nymph models and ballast weights
From this reading of the water, the choice of nymph, but above all its weighting, follows.
The aim is to offer an insect larva imitation (mayfly, whipworm mainly) at the right depth and drifting as inert and natural as possible. This is far from obvious.
The depth and speed of the current mean that we need to use tungsten balls of various shapes (drop, offset, classic) and weights. The balls used are generally between 2 and 5 mm. The most popular colors are gold, silver, copper and black. Today, however, they are available in a wide range of colors (chocolate, white, pink, etc.).
In practice :
Once the position has been visualized and the type of nymph and weighting adapted, you need to make one or more drifts to try to pass where you think the trout will be placed. If the fly passes too quickly and too high in the water layer, your weighting is too light. On the other hand, if your drift is too slow in relation to the speed of the surface current and your fly is rapidly hitting the bottom, your weighting is too heavy. With a little trial and error, you can quickly find the right weighting and get through as you should. But beware, if the first drifts are not good, the trout may already be on the alert! The ideal is therefore to get through on the first pass. The next step is to find the right ballast for each position, depending on current, depth and trout activity.
As far as patterns are concerned, pheasant tail and variants, hare's ear, natural dubbing flies, often two-tone, are very often used. Increasingly, anglers are using "perdigones" nymphs from Spain. It's a fashion statement, but their main advantage is that they are smooth and therefore sink faster. As a result, a lighter weight can be used for the same hook size.
Key detection and animation
To know that our nymphs are being taken by trout, and thus detect bites, we use a bite indicator, often made of two-tone "special nymph" thread.
But depending on technique and material, you can use a braided indicator, a yarn pompom or a small ball of colored dough.
In Euronymphing or Spanish or Czech nymph fishing, with rods specifically designed for this technique (between 10 and 11 feet for 2 to 4 line), a two-colour line of the same diameter as the line body is often used.
A tip length corresponding to the depth of the fishing station and a diameter adapted to the color of the water, the size of the fish and the wary nature of the fish must be placed under this indicator. Diameters between 16 and 10°, or even less, are often used, either in nylon or fluorocarbon.
You need to keep a constant eye on this indicator, which is carried by the current when the nymph's weighting is adapted to its speed, accompanying it with your arm and rod, and strike at the slightest anomaly. The touch is often characterized by a wriggling of the line, a lateral movement or a sharp stop. This is why you need to strike very quickly, but not too powerfully to avoid breaking the tip.
Most of the time, inert drifts should be made, letting the current carry the nymphs like an insect or larva carried by the current. However, it is sometimes a good idea to animate your flies on the spot or at the end of the drift to trigger the bites. On certain days or at certain times of the day, this is the key to fishing. This animation involves shaking your imitations, but above all raising the rod to bring the flies to the surface.
