Fly fishing’s imagery is all dry flies — the sip off the surface, the visible take. The fish’s menu disagrees: trout do an estimated 80–90% of their feeding underwater. Knowing what each fly type imitates tells you when each one earns a spot on your tippet.

What each type actually imitates

  • Dry flies float on the surface, imitating adult insects that have hatched or fallen in — mayflies, caddis, hoppers, ants. They work when fish are visibly rising.
  • Wet flies swing below the surface, imitating drowned adults, emerging insects mid-ascent, or small baitfish. The classic soft-hackle wet fly is the oldest pattern family in the sport.
  • Nymphs (a wet-fly subset that earned its own shelf) imitate the immature insect stage crawling or drifting near the bottom — where trout eat most of their calories, most days.
  • Streamers are the big wets: minnows, sculpins, leeches, stripped actively for the largest fish in the run.

The case for starting wet

Beginners are usually pointed at dry flies because the take is visible. But dries only produce during surface activity, which might be an hour a day in season — and zero hours in cold months. Subsurface flies produce all day, and a swung wet fly does most of the presentation work itself: cast across the current, let it swing, follow with the rod tip. Strikes come as a pull you can’t miss. It is the most forgiving technique in the sport, which is exactly what a first season needs.

Nymphing under an indicator (a small float, functionally) is the other high-percentage start — more rigging, more fish.

When dries genuinely win

  • Visible rises — rings on the water mean fish are looking up; match roughly the size and color of what’s hatching.
  • Summer terrestrials — hoppers, beetles, and ants near grassy banks from midsummer on, even with no hatch.
  • Small pocket water — a high-floating dry (Stimulator, Elk Hair Caddis) prospects fast water where fish decide in half a second.

Size matters more than exact pattern: carry each of your core patterns in sizes 12–18 and match the naturals you see.

A starter box that covers most water

  • Dries: Parachute Adams (14–18), Elk Hair Caddis (14–16), foam hopper (10–12)
  • Wets/soft hackles: Partridge & Orange (14–16), March Brown spider (12–14)
  • Nymphs: Pheasant Tail (14–18), Hare’s Ear (12–16), Zebra Midge (18–20), a beadhead of each
  • Streamer: Woolly Bugger, olive or black (8–10) — arguably the single most productive fly ever tied

That’s under a dozen patterns, and it covers a remarkable share of trout water in North America.

The short version

Fish rising: tie on a dry and enjoy the show. No rises (most of the time): swing a wet or drift a nymph, because that’s where the fish are eating. Buy patterns in multiple sizes rather than more patterns — and never leave without Woolly Buggers.