Choosing a fly line, a leader and a fly for the water in front of you
Explainer · Last reviewed 2026-08-19
Four questions in a fixed order — where in the water, how fast is it moving, what is being eaten, and what is the wind doing — which between them decide the line, the leader and the fly. The order matters more than any single answer.
A FLY ANGLER MAKES THREE CHOICES BEFORE CASTING AND THEY ARE NOT INDEPENDENT. The line decides what depth is reachable. The leader decides how the fly behaves at that depth. The fly decides what it is pretending to be. Choose them in the wrong order and the last two are corrections for a mistake made in the first.
SO THE ORDER IS: DEPTH, THEN FLOW, THEN FOOD, THEN WIND.
QUESTION ONE. WHERE IN THE WATER COLUMN ARE THE FISH FEEDING? This decides the line and nothing else does. Feeding at or in the surface film means a floating line, because nothing else presents there. Feeding in the upper metre or two, or in shallow water broken by wind, means an intermediate — a line that sinks slowly and evenly and does not form the belly a floater does in a chop. Feeding deep, or holding on the bed in cold water, means a sinking line, and the sink rate is chosen for the depth rather than for the speed. If you do not know, a floating line tells you the most: you can watch it, fish a weighted fly under it, and change depth by changing the fly and the leader.
QUESTION TWO. IS THE WATER MOVING? Current changes what the leader is for. In moving water the leader's job is largely to let the fly drift at the speed of the water, which argues for length and suppleness, and it is why a river leader is long. In still water the leader's job is to separate the fly from a line the fish can see and to control how fast the fly sinks, which argues for length in clear conditions and for something shorter and heavier when a large fly must turn over. In salt water the current is the tide and it usually decides where to stand rather than what to tie on.
QUESTION THREE. WHAT IS BEING EATEN, AND IS THAT ACTUALLY KNOWN? Insects, baitfish and crustaceans are three different fisheries with three different retrieves, and the retrieve matters more than the pattern. An insect drifts and is fished dead or nearly so. A baitfish swims steadily and flees in bursts. A crustacean darts and stops and goes down, never travelling far or steadily. Getting the movement wrong makes a perfect imitation useless, and getting the movement right makes an approximate one work.
QUESTION FOUR. WHAT IS THE WIND DOING? Wind is the constraint that overrides preferences. It decides whether a long fine leader can be turned over at all, whether a large air-resistant fly is castable, whether a shooting head is needed to reach the water, and frequently which bank can be fished. An angler who plans the first three answers and then meets a headwind has to revisit all of them, which is why it is a question rather than an afterthought.
AND THE ANSWER IS A RANGE RATHER THAN A SETUP. Every one of these questions has several defensible answers on any given day, and the reason to ask them in order is that it makes the trade-offs visible rather than making the choice for you.
Mapping the four questions onto what this catalogue actually holds
The procedure above ends without saying which record each answer points at, which is the defect the rig map was built to fix. This is the map, and it is deliberately explicit about where the catalogue holds nothing.
SURFACE OR IN THE FILM, MOVING WATER, INSECTS. Floating line, long supple leader, dead drift — `dry-fly-fishing`, with `fly-presentation` and `mending-line-and-what-it-is-for` for the drift itself and `matching-the-hatch-what-it-means-and-when-it-is-wrong` for the pattern question and its limits.
BELOW THE SURFACE, MOVING WATER, INSECTS. Floating or intermediate line, weighted fly, detection as the real problem — `nymphing`, with `strike-indicators-and-when-they-help` for the detection and `choosing-a-fly-size-and-what-the-numbers-mean` for the fly.
STILL WATER, DEPTH UNKNOWN. This is where the line does the searching — `floating-sinking-and-intermediate-fly-lines` and `stillwater-fly-fishing`. The intermediate is the answer for the top few metres in a chop and the catalogue is explicit that it is a distinct density rather than a compromise.
STILL OR SLOW WATER, FISH EATING SMALL FISH. A streamer, fished with movement rather than drift — `the-four-fly-types-and-what-each-imitates` for what a streamer is doing and `fly-fishing-for-predators-pike-bass-and-beyond` where the quarry has teeth and the leader becomes a trace.
SALT WATER, SHORE, DISTANCE NEEDED, WIND. `shooting-heads-and-saltwater-fly-lines` for the line, `the-double-haul-and-casting-in-wind` for delivering it, `saltwater-fly-fishing-what-changes` for the tide and the line management, and `coastal-fly-fishing-safety` because the ground this is done from is the hazard.
SHALLOW, CLEAR, FISH VISIBLE. `sight-fishing-and-blind-searching` decides the whole approach before any tackle question arises, and it applies in a British harbour as much as on a tropical flat.
HARD BOTTOM, FISH EATING CRABS AND SHRIMPS. `crustacean-imitation-in-saltwater-fly`, where the sink rate and the retrieve are the fly and the outline is secondary.
BIG RIVER, SALMON, NO ROOM BEHIND. `spey-and-two-handed-casting-concepts`, which is a delivery answer rather than a presentation one and is the only entry here chosen by the bank rather than by the fish.
AND THE MOST COMMON REAL SITUATION IS NOT ON THIS LIST. Arriving at unfamiliar water with nothing showing, no hatch, and no visible fish is the ordinary case, and the honest answer is a floating line, a weighted fly and a systematic search of the likely holding water — because it is the setup that tells you the most about a water you know nothing about, not because it is the best one.
Practitioner consensus
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density against depth and temperature, leader construction, and selecting a fly against the food actually present.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: British game angling practice across river and stillwater, including the presentation each water and each quarry demands.States this directlyCitation checked — the work exists and is described correctly
- Freshwater Fishing — Macdonald & Jane's, 1975 (Specialist angling publication)Relied on for: Comprehensive angling practice including fly fishing across rivers and stillwaters and the tackle each requires.States this directlyCitation checked — the work exists and is described correctly
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated descriptions of established fly-fishing convention, recorded as practitioner consensus rather than as scholarship.Background and mechanism onlyCitation checked — the work exists and is described correctly
What this catalogue cannot answer for a fly angler, named rather than implied
A decision map is only trustworthy if it says where it stops. These are the fly questions FishingHQ currently holds nothing useful for, and they are checked against the catalogue each sprint rather than trusted to have stayed true.
NO PATTERN CATALOGUE, AND THAT IS A DECISION RATHER THAN A GAP. `fly-tying-concepts-without-the-pattern-catalogue` explains why: a list of dressings is a list, it goes out of date, it varies by region and by fashion, and the useful knowledge is what a fly is doing rather than what it is called. A reader who wants to know which named fly to buy will not find it here and is not being failed by that.
NO EUROPEAN NYMPHING SYSTEM IN DETAIL. The catalogue holds `nymphing` and holds nothing on the contact-nymphing styles — long leaders, coloured sighters, no fly line beyond the tip — that have changed river fishing substantially. That is a genuine absence rather than a refusal.
NO STILLWATER BOAT FISHING. Drifting a boat, drogues, loch-style fishing and the whole northern and Irish tradition built on it are absent. `stillwater-fly-fishing` is written from the bank.
NO SALTWATER FLY BEYOND THE SHORE. Boat fly fishing, teasing, and the offshore work that a great deal of tropical fly fishing consists of are not held.
NO FLY FISHING FOR CARP, and it is a real fishery on both sides of the Atlantic, sitting squarely in the gap `where-fly-fishing-goes-beyond-trout` opens and does not fill.
AND NO RECOMMENDATION OF A SETUP TO BUY. That is refused permanently rather than absent temporarily, on the same grounds the tool ledger refuses a fly selector: it is a commercial surface wearing an advice label, and the catalogue has no evidence that would support one.
Practitioner consensus
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density against depth and temperature, leader construction, and selecting a fly against the food actually present.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: British game angling practice across river and stillwater, including the presentation each water and each quarry demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, and the ground and tide states each is fished over.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Habitat association and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
Where to go next
Where it matters
- Dry fly fishingOne of the four answers the spine's first question can produce — surface, moving water, insects — and reachable from the procedure rather than only by knowing to look for it.
- Fly fishingThe discipline record explains why fly tackle works and does not say how to choose it for a particular piece of water. This is the record that puts the pillar's twenty-nine explainers in an order, on the pattern the rigs pillar established.
- NymphingThe answer to the spine's commonest case on a river: no rises, fish holding low, and detection rather than imitation as the real problem.
- Saltwater fly fishingWhere the spine's second and fourth questions dominate: the tide replaces the hatch, and the wind decides what is castable at all.
- Stillwater fly fishingWhere the spine's first question — where in the water column — has no current to answer it, so the line does the searching.
What these connections rest on (5)
Practitioner consensus — 5 connections
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
Dry fly fishing
The decision record joined to the disciplines and methods it orders, so that a reader arriving at any of them can reach the procedure rather than having to already know it exists. This is the shape `choosing-a-rig-for-the-conditions` established for rigs.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density and depth, leader construction, fly selection against the food present, and the behaviour of stocked and wild trout in still water.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British game angling practice: river and stillwater trout, grayling and salmon fishing, and the presentation each demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, the ground each is found over and the presentation each takes.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Distribution, habitat and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
Fly fishing
The decision record joined to the disciplines and methods it orders, so that a reader arriving at any of them can reach the procedure rather than having to already know it exists. This is the shape `choosing-a-rig-for-the-conditions` established for rigs.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density and depth, leader construction, fly selection against the food present, and the behaviour of stocked and wild trout in still water.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British game angling practice: river and stillwater trout, grayling and salmon fishing, and the presentation each demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, the ground each is found over and the presentation each takes.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Distribution, habitat and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
Nymphing
The decision record joined to the disciplines and methods it orders, so that a reader arriving at any of them can reach the procedure rather than having to already know it exists. This is the shape `choosing-a-rig-for-the-conditions` established for rigs.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density and depth, leader construction, fly selection against the food present, and the behaviour of stocked and wild trout in still water.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British game angling practice: river and stillwater trout, grayling and salmon fishing, and the presentation each demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, the ground each is found over and the presentation each takes.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Distribution, habitat and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
Saltwater fly fishing
The decision record joined to the disciplines and methods it orders, so that a reader arriving at any of them can reach the procedure rather than having to already know it exists. This is the shape `choosing-a-rig-for-the-conditions` established for rigs.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density and depth, leader construction, fly selection against the food present, and the behaviour of stocked and wild trout in still water.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British game angling practice: river and stillwater trout, grayling and salmon fishing, and the presentation each demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, the ground each is found over and the presentation each takes.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Distribution, habitat and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
Stillwater fly fishing
The decision record joined to the disciplines and methods it orders, so that a reader arriving at any of them can reach the procedure rather than having to already know it exists. This is the shape `choosing-a-rig-for-the-conditions` established for rigs.
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density and depth, leader construction, fly selection against the food present, and the behaviour of stocked and wild trout in still water.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British game angling practice: river and stillwater trout, grayling and salmon fishing, and the presentation each demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, the ground each is found over and the presentation each takes.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Distribution, habitat and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
Sources for this page
- Still Water Fly-Fishing — Andre Deutsch, 1952 (Specialist angling publication)Relied on for: Stillwater fly practice: line density against depth and temperature, leader construction, and selecting a fly against the food actually present.States this directlyCitation checked — the work exists and is described correctly
- Trout & Salmon — Bauer Media (Specialist angling publication)Relied on for: British game angling practice across river and stillwater, including the presentation each water and each quarry demands.States this directlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: British sea angling practice including shore fishing for bass, pollack and mullet, and the ground and tide states each is fished over.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Habitat association and feeding biology of coastal and tropical marine species, from regional identification guides prepared for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
- Freshwater Fishing — Macdonald & Jane's, 1975 (Specialist angling publication)Relied on for: Comprehensive angling practice including fly fishing across rivers and stillwaters and the tackle each requires.States this directlyCitation checked — the work exists and is described correctly
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated descriptions of established fly-fishing convention, recorded as practitioner consensus rather than as scholarship.Background and mechanism onlyCitation checked — the work exists and is described correctly
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