Since trout take most of their food below the water’s surface, nymph fishing is perhaps the deadliest type of fly-fishing.
Nymph fishing in its literal sense is angling with the imitations of immature insects such as mayflies, caddis flies, midges and others. But it also applies to other underwater creatures such as shrimps and corixas (lesser water boatmen). Even snails are labelled under the term ‘nymph’.
Getting set up
Nymph fishing on rivers requires light fly line – AFTMA 4, 5 or 6 – to present the fly delicately without slapping the water. It doesn’t matter what the taper or colour of the line is – as long as it floats. A rod with a fast action (middle-to-tip) and 2.6-2.9m long is ideal.
Leaders should always be somewhat longer than the depth you are fishing. For example, deep runs and holes of 2.7m (9ft) require a 3.7-4.6m (12-15ft) leader. For general fishing conditions, though, a 2.7-3.7m (9-12ft) leader is best. To extend the life of a knotless tapered leader, add a tippet section to the end. You then have to replace only the tippet when it’s used up, not the entire leader.
Since river fish usually don’t grow as big as their reservoir cousins, consider the pliability of the line and the size of the fly when choosing the proper tippet breaking strain. Soft line allows the nymph to move freely and easily in the water, imitating a natural, free-swimming insect. Stiff or thick line hinders the nymph’s movement and puts fish off. As a general guideline, hook sizes 18-20 require 1 ¼ -2lb (0.7-0.9kg) line. You may need 3-4lb (1.4-1.8kg) line for hook sizes 12-16. Heavily weighted patterns in sizes 6-10 require line up to 5-6lb (2.3-2.7kg).
The upstream approach
One of the most celebrated and effective methods is the upstream approach. There are two basic variations of this style of fishing, the dead drift and the induced take.
The dead drift is simply casting upstream of a trout (or a likely lie) and allowing the fly to run with the current towards the fish. The induced take is similar to the dead drift, but just as the fly is about to reach the quarry, move the nymph either sideways or upwards by quickly lifting up the rod tip while pulling the fly line. This imitates a fleeing, panic-stricken insect and stimulates the trout to feed.
Water craft is vital when fishing upstream: you should have a good idea where the trout are, or where they are likely to be, so that you don’t waste time fishing in inappropriate stretches of water such as shallow runs only about 15cm (6in) deep.
Another important yet often overlooked consideration is choosing a correctly weighted pattern which fishes at the trout’s level. If a trout’s lie is just off the bottom in very deep fast water, for example, you need a heavy nymph to get right down to the fish. The alternative is to cast far enough ahead of the lie so that the fly has extra time to sink to the required depth.
Whether you use the dead drift or the induced-take method of upstream nymphing, keep a low profile – kneel on the bank or cast from behind the cover of tall grass.
Another point which may help you catch wary trout in clear rivers is to change the angle ofyour cast. Ifyou are casting to a trout directly upstream, your line lands above the feeding fish – this could spook the trout. But by casting upstream and across, you place the line and leader at a slight angle to the fish, helping to conceal the fly line. In clear water – where you can see the fish – detecting the take isn’t difficult. A trout or grayling’s sudden movement upwards, downwards or to the side usually indicates that the fish has hit your nymph. A speedy but gentle lift of the rod sets the hook. Whatever the water conditions, if you don’t see a fish but your leader stops or twitches in the current, strike! Your attitude should always be to strike first – ask questions later. Trout and grayling can sometimes spit out imitations as quickly as they take them.
When trout are surface-feeding the same principles of upstream nymphing apply though there are distinct parallels with dry-fly fishing. G.E.M. Skues founded this style of angling in the early 1900s; later it came to be called ‘emerger’ or ‘damp’ fly-fishing. Follow the same principles as with the dead- drift method, but use a pattern (such as a sedge pupa emerger) which hangs in the surface film, and cast closer to, but still upstream of, the rising trout or grayling. Takes are again visual. They look like an ordinary rise – if you see one anywhere near your fly, set the hook immediately.
The basic upstream nymph tactic is applicable throughout the season, and by varying the weight and style of your artificial you can accommodate everything from the surface-feeding brownie to the bottom-grubbing grayling.
Down stream nymphing
Another method of nymph fishing is the traditional ‘down and across’ technique. Drag on the nymph isn’t too much of a disadvantage when fishing downstream. Cast across the stream and let the current sweep the nymph down. This is one of the easiest methods of fly-fishing because there isn’t much casting involved.
By controlling the line flow, you’re not limited to imitation solely by appearance -you can make a heavily weighted nymph, for example, ‘swim’ in a deep pool by gently twitching the fly upstream and then letting it move down again. This adds life to the nymph.
Water craft isn’t as important when fishing downstream. An intimate knowledge of the river’s deep pools and seething eddies isn’t necessary because your nymph covers a wide fish-holding area, and you take a few steps downstream after working a stretch.
Unlike fishing upstream – when the current has control of the fly – ‘nymphing’ downstream allows you to dangle a tantalizing fly just above a sunken log, a boulder or a snag-strewn heap of branches: you can explore the river without worrying too much about losing your favourite fly.
There are certain disadvantages when fishing downstream, though. First of all, you can sometimes be visible to the trout. The importance of stealth cannot be over-stressed. Walk quietly to the bank; fish from the cover of vegetation; and wear drab clothing. This is especially important on calm stretches of shallow water. Fish with a lot of line out in such places.
A second disadvantage comes when you try to read takes. Generally, you can feel them more than you can see them. If you’re not careful and controlled when setting the hook, you could easily pull the nymph away from the trout’s mouth (since the fish usually points or faces towards you).
Hooking isn’t usually a problem when you’re fishing upstream because the trout is in front of you or at your side – striking pulls the hook into the fish’s mouth.
Some say fishing the nymph is much more problematic than using the dry fly (especially when detecting takes). But this deadly style of fly-fishing isn’t beyond the reach of anyone. Proficiency and confidence come with practice and patience.