Small stream nymphing is a very productive form of fly fishing.
At times, you will not rise a fish to a dry fly. Yet there are
fish feeding actively below the surface. So, you put the fly
(nymph) to the fish.

Nymph fishing is probably the most challenging of all fly fishing
techniques. Since the fly is underwater and is often extremely
small, nymph fishing can test the abilities of any angler, and
often leaves the beginner angler extremely frustrated. Yet, the
ability of having a good nymph fishing technique is essential for
productive trout fishing. The reason for this is simple - most
trout have a diet that consists primarily of sub-surface insects
(nymphs). An angler who does not know how to nymph fish will be
greatly limited on where they can fish and what they use.

This ebook will hopefully provide some information for any angler
who is in search of how to improve their nymph fishing abilities
while fly fishing.

While this book provides more information than any other resource
on the Internet about fly fishing with nymphs, ultimately, the
only way to learn this technique is to go out and do it. From
initial frustrations will come mastery over time.
What exactly is Nymph Fishing?

Let's start at the basics. Nymphs are, as defined by the
Meriam-Webster dictionary : "any of various immature insects;
especially : a larva of an insect (as a grasshopper, true bug, or
mayfly) with incomplete metamorphosis that differs from the imago
especially in size and in its incompletely developed wings and
genitalia"

In everyday terms, nymphs are aquatic insects that are still in
their underwater stage, as in not yet having reached their adult,
or flying stage of life. One thing worth remembering is that, if
you enjoy dry fly fishing, all the flies you see on the water are
adult insects. These insects have "grown up" from their
underwater stage and have taken to the air for their mating
rituals. In essence, dry fly fishing involves using fly
imitations that involve imitations of the adult aquatic insect
(such as a mayfly, caddis fly or stonefly). By contrast, when
nymph fly fishing, the angler attempts to imitate the younger,
underwater stage of these exact same flies.