Walk into any fly shop and you’ll quickly see rows upon rows of patterns in different shapes, sizes, and colours. For newcomers, it can feel overwhelming – what’s the difference between a dry fly, a wet fly, a nymph, a streamer, and an emerger? More importantly, when do you use them?
Let’s break it down in plain English.
Dry Flies – Fishing on the Surface
A dry fly is designed to float on the water, imitating insects that trout see drifting or hatching on the surface. These are the flies you picture in classic chalkstream scenes – a fish rising, a carefully placed cast, and a gentle sip off the top.
- When to use: During hatches, when you see fish rising or sipping insects.
- Patterns you’ll recognise: Adams, Blue Winged Olive, Elk Hair Caddis, Griffith’s Gnat.
- Why they work: Trout watch the surface intently – an easy meal drifting right above them.
Dry fly fishing is visual, exciting, and one of the most satisfying ways to catch a trout.
Wet Flies – Traditional Subsurface Patterns
A wet fly is designed to sink below the surface and drift or swing in the current. Many traditional North Country spider patterns fall into this category, their soft hackles pulsing as they move.
- When to use: When fish aren’t visibly rising but may be feeding mid-water.
- Patterns you’ll recognise: March Brown Spider, Black Spider, Snipe & Purple.
- Why they work: The impression of movement – the hackle fibres breathe in the current, suggesting life even if the pattern doesn’t match a specific insect.
Wet flies are forgiving, versatile, and brilliant on rivers when trout are looking up and down the water column.
Nymphs – Matching What Fish Eat Most
A nymph imitates the underwater life stages of insects such as olives or stoneflies. Since trout and grayling take the majority of their food subsurface, nymphing is often the most reliable way to catch fish.
- When to use: Almost any time, especially when no surface activity is visible.
- Patterns you’ll recognise: Pheasant Tail Nymph, Hare’s Ear, Perdigon
- Why they work: They imitate the real bugs drifting or crawling along the riverbed – what trout actually eat day in, day out.
Modern techniques like Euro-nymphing have made nymph fishing even more effective, but even a simple weighted Pheasant Tail fished upstream can transform your catch rate.
Emergers – Caught Between Two Worlds
An emerger imitates an insect struggling in that critical moment when it’s hatching from the nymph stage into a winged adult. This stage is when insects are most vulnerable, trapped in the surface film. Trout know this, and they’ll often focus on emergers rather than fully hatched adults.
- When to use: When fish are rising but refusing classic dries – often during hatches.
- Patterns you’ll recognise: Klinkhåmer Special, Shuttlecock Emerger, CDC Emerger.
- Why they work: They sit in the surface rather than on top, perfectly matching what trout are eating at that tricky stage.
The Klinkhåmer, for example, is deadly on UK rivers – part submerged body, part visible wing post, giving you the best of both worlds: visibility for the angler and realism for the fish.
Streamers – Big Meals for Big Fish
A streamer is a larger fly that imitates fry, leeches, or other prey fish. Instead of drifting passively, streamers are actively pulled through the water with strips or swings.
- When to use: In higher water, on stillwaters, or when targeting aggressive trout, perch, or pike.
- Patterns you’ll recognise: Woolly Bugger, Zonker.
- Why they work: They trigger aggression as much as hunger – a trout or predator often can’t resist chasing a moving meal.
Streamer fishing is dynamic and exciting – don’t be surprised if your heart skips a beat when a big trout slams into one.
Putting It All Together
Think of these fly types as tools in your box:
- Dry flies – imitate insects on the surface.
- Wet flies – traditional patterns fished just below.
- Nymphs – the most consistent food source, fished near the bottom.
- Emergers – stuck in the surface film, irresistible during hatches.
- Streamers – big patterns representing baitfish and other large prey.
No single type is “best” – it’s about matching your choice to the conditions, what the fish are doing, and what the river or lake is telling you.
Tip: If you’re building your first fly box, carry a few of each type. A couple of dries, a handful of nymphs, one or two emergers like the Klinkhåmer, some simple wets, and a streamer or two will cover almost every situation you’ll face on UK waters.
