Let’s start at basics. Nymphs are, as defined by 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 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 flies you see on water are adult insects. These insects have “grown up” from their underwater stage and have taken to air for their mating rituals. In essence, dry fly fishing involves using fly imitations that involve imitations of adult aquatic insect (such as a mayfly, caddis fly or stonefly). By contrast, when nymph fly fishing, angler attempts to imitate younger, underwater stage of these exact same flies.

Strikes on a nymph fished in this manner can occur anytime since nymph is floating drag free. Always follow strike indicator using this method, setting hook immediately whenever you see strike indicator stop momentarily in water or suddenly change direction. With practice, you’ll get a feel for what differentiates a “rock strike” from a “trout strike”.

Also, don’t be in to big a hurry to pick up nymph. You can let it float right down almost to your feet (within 5-10 feet), assuming you didn’t make too much of a commotion during your wading (thus scaring away all fish near you). Remember, trout will be facing against current waiting for their food to arrive – and you’ll be downstream from them. Thus, they won’t see you unless you make lots of noise to let them know that you are there.

The other reason you want nymph to continue floating towards you is because you want to nymph to come up from bottom of river a bit – which simulates an emerging insect. As nymph gets closer to you, simply raise rod tip a bit. This will bring nymph off bottom of river and put it in a gradual, but still downstream, incline towards surface.

Once you pick up fly, you will then want to wade just a bit to your right or left, then make another cast, allowing nymph to dead drift through another spot in river that is just a bit away from where your nymph previously floated through. By doing things this way, you can cover a lot of water in a hurry – in a very effective manner.