Anglers have sought the enigmatic summer sea trout (sewin is their Welsh name) since the dawn of time, and just a lucky few learn the secrets of success with this most elusive of all game fishes. For most anglers, sea trout remain forever a fish of their dreams. Experts say it is probably the shortage of food that drives so many young trout to leave their rivers and run away to sea. Young men have been doing that for centuries, but with sea trout it is the ladies who take the initiative. Not entirely, but mainly: on the River Teifi in Wales, for example, two out of every three sea trout are female, while of the resident brown trout population the majority are cock fish. Perhaps the more aggressive nature of young males leaves the young hen fish with a choice of starvation rations or a trip to the seaside.
When you catch a sea trout, it's quite easy to see whether it is a hen fish or a cock fish. The hens have deeper bellies, more rounded snouts, and no sign of a hook, or kype, on the lower jaw. Note that I say 'when' rather than 'if'.
Our aim in preparing this section of our online flyfishing guide was to take the mystery (but certainly not the magic) out of this challenging branch of flyfishing and to provide some straightforward guidelines that will help you to tackle up and get started in this fascinating branch of flyfishing.
If you are a reasonably competent trout or salmon flyfisher, then we urge you to have a go at sea trout, but if you are still struggling with the basics of trout or salmon fishing then we strongly suggest you work on those areas first, because even for experts sea trout fishing is far from easy.
Big sea trout do not feed while in rivers. That's not to say that a sea trout will not take an insect or some other small creature occasionally; they will, but for the most part when a sea trout takes your fly it is not because it is driven by the need to feed.
Estuary fishing for sea trout is also popular but either spinners or bait are commonly used, although it is certainly possible to flyfish for sea trout in shallow salt water provide there the area is not heavily choked with seaweed.
Sea trout feed on sandeels when at sea, and in estuaries an imitation sandeel 'fly' is well worth a try.
The emphasis in this online guide is on the essential knowledge required to fish for sea trout in rivers, mainly at dusk or in darkness because when rivers run clear the sea trout hide during daylight, seeking the cover of tree roots and undercuts. When they emerge as darkness descends it is possible to catch them on a fly... but it's far from easy and very much dependent on the skill and knowledge of the flyfisher.
The experience and skills necessary for competence in sea trout fishing really do have to be acquired at the waterside, but they can only come if you have a good basic understanding of sea trout behaviour and the basic techniques necessary to catch them. In particular there are two factors that make all the difference:
In many rivers the future of sea trout stocks (and especially large fish) is seriously threatened. In England and Wales there are strict statutory bag klimits and restrictions on taking both undersized and large sea trout.
If you visit a river where there is known to be a sustainable harvestable surplus, you may be allowed to take the occasional fish; however, knowing that cooked sea trout do not spawn we choose to return all of the sea trout that we catch. Please see our guidelines on best practice catch and release and our online length-to-weight converter.
In order to get the most out of sea trout fishing, you wil need matched tackle that is set up to suit the location and river conditions in which you will be fishing.
It is perfectly possible to use your ordinary trout fishing rod for sea trout fishing - or even, particularly in high water conditions, to use a small double-handed rod of the kind commonly used for salmon fishing; however, whichever rod you use, a good tackle setup can mean the difference between success and failure.
In the advice presented here, (J-B) indicates a link to our Jargon-Buster page of plain English explanations of technical terms.
If you can afford to buy only one set of tackle it is possible to choose a rod which will work perfectly well for both trout fishing and sea trout fishing provided you make the necessary changes in leader set up and the flies that you use. A good compromise would be a 9 to 9.5ft #6 or #7 fly rod. The 'action' of the rod should not be too stiff as sea trout can be very unforgiving once you hook them, and if you and the sea trout pull in opposite directions at the same time, you will almost certainly lose the fish, the fly and probably the leader too.
Pat uses his 9.5ft trout rod for both trout and sea trout fishing, but I prefer to use a slightly heavier and more flexible rod for sea trout fishing, resorting to a 9.5ft #7 rod when the sun goes down and my inclinations turn towards sea trout. Because my sea trout rod is slightly softer in its action, it helps me in two ways: firstly I am able to spey cast it with less effort, and secondly, the softer and more flexible tip of the rod is more forgiving when a sea trout becomes immediately airborne once it is hooked.
Some people prefer to use heavier and longer fly rods for sea trout fishing - a 10ft #9 or #10 rod, for instance, but these heavy lines are more tiring to cast - and if you are fishing in confined spaces, 10ft of fishing rod can be a distinct disadvantage. Such rods are better kept for fishing on large windy lakes or reservoirs, in our opinion.
Once you have decided on your fishing rod, you will need a reel that will easily accommodate plenty of backing (once they are hooked, sea trout often make runs as impressive as those made by salmon) as well as your chosen floating fly line. Buy a reel that has a spare spool so that you can load it with either an intermediate (slow sinking) line or a fast sinker; this will be very useful when you encounter fast and high water conditions.
You will also need a sink tip extension (such as a poly leader) for your floating line. Changing to a sink tip and a slightly heavier fly is often all you need to do to get your fly down deep enough to attract a sea trout.
Except when using very large and heavy flies (which should be tied on leaders no more than a metre (3ft) in length, tapering your leader (either by ting section in gradually reducing breaking strains or by using a continuously-tapered factory-made leader) is still just as important for sea trout fishing as it is for trout fishing, because it is easier to cast and will create fewer tangles. The leader should taper to not less than 3,5kg (8 lbs) breaking strain, and once your casting is up to the challenge you might want to tie on at least one dropper which can accommodate a second fly. Fishing with a team of two, or even three flies, greatly increases your chances of catching sea trout.
For fishing at night you will need a good torch to help you to get to and from the river and to help when making changes to tackle setup - although you should never shine the torch on the water where you plan to fish. Sea trout abhor light and will very quickly retreat to a place where you cannot possibly catch them. There are numerous types of torches available through tackle shops, but a head-mounted light leaves both hands free to change leaders or flies.
Sea trout fishing evenings frequently turn into almost all-night sessions and so you should be prepared for dramatic drops in temperatures and take warm and waterproof clothing. We have known air temperature drops around the River Teifi of well in excess of 10 degrees once the sun sets. We also always take a flask with hot coffee and a supply of sweet biscuits or cakes with us to boost flagging energy levels or simply to cheer ourselves up when the sea trout are not being cooperative!
Welcome to our online guide to selection and tying of flies and surface lures for various weather and water conditions on rivers, streams and estuary waters.
You might be surprised to see that we do not have on display a vast selection of sea trout flies in a bewildering array of colours. That's because more than forty years of sea trout fishing experience has taught us that fly pattern and colour are two of the least important factors when fishing for sea trout at night - and night time fishing is by far the most productive when rivers are running clear in spring and summer. In most situations when sea trout fishing you are not trying to imitate any particular insect or other creature that the sea trout might recognise as food, an so matching the size, shape, colour or even behaviour of a food creature is not an issue.
There are exceptional circumstances, when sea trout may be feeding by day or at dusk, but that is far from the norm.
The first question to ask is 'Why do sea trout take our flies?'. The only honest answer is nobody knows. We can only conjecture that:
Yes, they do feed... but not much, and large sea trout hardly ever feed - they, like salmon, don't need food because they can live off their body fat for many months. Small sea trout (whitling, herling, peal... they have many local names) certainly will feed at times, taking nymphs and larvae from the riverbed and even rising to take flies floating on the surface. This happens most particularly during dull weather and when the river is somewhat coloured after heavy rain.
We have caught plenty of small sea trout - up to about 4lbs (1.8kg) - on nymphs and dry flies. If you see what look to be large trout sipping flies from the surface then the best advice we can give is this: Match the Hatch. Use a fly of similar size and shape as the natural insect. In dull weather there may even be an advantage in getting the colour more or less right, but on bright days when fish are feeding in open water the colour doesn't matter at all because all the fish sees is a silhouette. For upwinged flies a Greenwell's Glory or similar dry fly is ideal, and sizes 12 to 16 will match most of the natural insects you are likely to encounter in Britain and Ireland. the Mayfly is a notable exception, and a size 8 dry fly such as Grey Wulff or even a Mayfly imitation will be handy at such times. Any general-purpose nymph pattern will do if the sea trout are taking sub-surface food - Pheasant Tail and Gold-ribbed Hare's Ear are equally effective.
Imitative flyfishing for trout does not require very many flies, and the same applies when sea trout are feeding on insects. We manage very well with just seven patterns in a range of sizes, so our fly boxes are not confusing jungles of long-forgotten patterns. See Pat O'Reilly's Matching the Hatch for full details of what we consider to be The Magnificent Seven.
Big sea trout tuck their heads into holes in the riverbank by day, and then they are uncatchable. At dusk and well into the night they move out and stretch their fins, sometimes leaping and splashing so that you know where they are, but more often staying deep down on the riverbed. A fly put in front of a sea trout's nose and then moved enticingly will often provoke a take, either violent or gentle. Here are the requirements of such a fly:
Traditional wet flies can be used for sea trout fishing, but we recommend one important modification: cut off and dressing material that extends beyond the bend of the hook. This is because sea trout so often come at a fly from behind, following it across the river - sometimes right into the shallows on the bank from which you are fishing, periodically nipping at the 'tail end'. Striking at these nips is pointless: Streamer flies are poor for sea trout fishing, because so few takes result in fish being hooked.
Durability is a consideration, too: sea trout have very sharp teeth and can shred a fly that is tied using soft materials such as peacock herl. Alexandra (pictured on the left), a popular traditional pattern with a peacock herl wing, is therefore not on our 'recommended list'.
These are patterns that we can recommend:
Better than any of them, in our experience, is a very simple fly that you can't buy in shops but you should find very easy to tie. It is called the Sparker, and was devised by Sue Parker. It's simply a sparkly tinsel-winged fly with or without a brass bead head. The winging material is Lureflash, and Sue ties them in various colours - red, blue, pearl, copper and yellow - just to add variety to her fly box; the sea trout don't seem to mind at all what colour you use, probably because once it is dark they, like us, can't distinguish colours.
Here (pictured on the right) is one that Sue made earlier. Tie these super sea trout flies in sizes 10, 8, 6, 4 and 2, and if you want to achieve maximum depth then include a brass or tungsten bead head of a size to suit the hook.
When it gets really dark, you will need to use big flies, and our fly boxes always include simple patterns tied as:
What about sizes? We suggest you stock up with a few of each of the following: 1/2, 1, 2, 4 and 6 inches (1, 2.5, 5, 10 and 12.5cm) tube length, and 2, 4 and 6 inch (5, 10 and 12.5cm) bar length in the case of Waddington lures. Hooks should be size 10 singles or size 12 doubles regardless of lure length.
The tying pattern is not important, but always use a durable winging material such as calf tail (as in the tube fly pictured on the right) or, better still in our experience, a modern synthetic material such as heavy weight Lureflash tinsel that will not trap any air: this is what you need to get flies down deep quickly, before they have been swept out of the target zone by a fast current. If you make Sparker Waddingtons and Sparker tube flies your standard ammunition for deep-water late-at-night sea trout fishing you really can't go wrong.
Of course, learning to cast these big flies safely is crucial - to learn how to do so, see our online Casting Instruction...
Also known as Wake Flies, surface lures are simply flies that float. When dragged across a calm surface, a wake fly creates... well, a wake! The idea is very simple: When the night is so dark that even a large fly fished near the riverbed (which is where sea trout lie nearly all of the time - they don't hover in mid water) is unlikely to be seen by a sea trout unless it comes right up against the fish's nose, a wake across the surface is much more visible. Don't ask why, but even a very big sea trout deep down in a dark pool can be provoked into surging upwards and seizing the fly.
As you can imagine, the fly is simply a silhouettes, and indeed where it not for the huge wake streaming behind it the fly itself would probably go unnoticed. As it is, the takes to surface lures can be very exciting indeed, as the fish surge upwards breaking the surface like missiles launched from submarines.
Any floating fly will do. For example, a Muddler Minnow is a very effective surface lure, although it has the minor disadvantage of tending to lose its buoyancy after a few sea trout have seized it and swamped it. (Never add floatant to a Muddler Minnow - or any other dry fly made using the hollow fibres of deer hair, because once floatant fills up the hollow fibres they become less buoyant and with the added weight of the hook they may sink rather than float - it will be no use then as a wake fly.)
We make our own surface lures using white Ethafoam cut into small triangles and whipped to a hook just behind the eye. Simple, but very effective and durable, these are surface lures that will never sink. Why use white foam if sea trout see only a silhouette? Simply because we can see a white fly at quite some distance even on a dark night, and so we know where on the river we are casting it - or if our fly goes astray we know which tree it is stuck in!
Large sea trout are difficult to catch. Partly it's because they very rarely feed, so trout-fishing tactics are ineffective and you have to lure them some other way; and they so rarely take a fly by day unless the river is high and coloured
But there's more to it than that: sea trout are difficult to locate - at least until you get used to it, so most of the river is devoid of fish, and if you simply 'fish the water' at random you can expect a very lean time.
In this section, therefore, we will cover the following key aspects:
In many ways, when sea trout are seen feeding either on dry flies or on emergers (nymphs about to eclode and become winged insects) they are as easy and sometimes even easier to catch than resident brown trout. This is because they rarely become preoccupied with one particular insect at one particular stage in its lifecycle - for example nymph, emerger, dun, spinner, or spent spinner. Almost any fly of roughly the same size as or slightly larger than the natural insect will do. As for how to fish with imitative flies and nymphs, the techniques are identical to those you use when fishing for trout and grayling, and so for details of a suitable basic set of flies and how to fish with them, see our Trout Fishing section - or better still get a signed copy of Matching the Hatch and you will be set up for flyfishing whether your quarry is a trout, a grayling or a feeding sea trout.
It is unusual to catch a sea trout bigger than 1.5kg (3.5lb) using dry flies, although occasionally a big sea trout will take a smallish nymph. For this reason although you may have to use a leader tippet as fine as 1.5kg (3.5lb) breaking strain to present a small dry fly without excessive drag, when nymph fishing there is no need to fish so fine and we recommend 2.5kg (6lb) breaking strain as a minimum tippet strength.
In spring - and indeed at any time in the season when the river rises and becomes coloured, sea trout can be caught by day as they run up river. In bright sunny weather your best chance is to fish where there is plenty of tree cover. Cast your fly from such a position that you can bring it slowly across the run line and as deep as possible without snagging on the riverbed.
In all but the heaviest of currents it is on the main channel - the deepest part of the river, where if you were to see it in drought there would still be a trickle of water. Trout fishers are used to seeing food lanes coincident with the run line - it's where the dead leaves, scum and other debris (including trapped flies) drift along. On a bend, unless hard rock determines the shape of the riverbed and banks, the main channel will be near to the outside of the bend, which will also be the deeper side of the river. the sharper the bend, the nearer to the bank the main channel, and any running fish, will be.
In the picture on the left, the river is flowing from left to right, and the red line denotes the main channel - the run line in all but a major flood.
At each bend in the river, the main channel switches from one bank to the other, always cutting more deeply into the material of the riverbed where the bend is sharpest, and at such points the channel is deepest and closest to the outside of the bend, where the bank is eroding and may well be undercut. (See our Safety Guide...)
The bright green oval shapes in the picture above denote sea trout hot spots; they are points at which a sea trout benefits from the shade provided by overhanging trees, and the darker it is the less fearful and easier to tempt sea trout seem to become.
Often, then, you will be able to fish from the deeper side of the river, but you will need to stand back a bit and to crouch low, otherwise you might spook the fish - yes, even in coloured water. If a fish can see your fly, then light must be penetrating deep down, and a fish can equally see movements on the riverbank. Stand still and avoid sudden movements if you choose to fish from a high bank.
Fishing from the shallow side means that you are further away from your quarry. On a small river, you may still be control of the movement of your fly so that it spends a fair proportion of the time in the vicinity of the run line. Anywhere else and your fly will not be seen by any running fish.
Confidence is crucial when sea trout fishing. It is the dead of night, you are casting your flies in near darkness, and you will have but a split second to react if a sea trout seizes your fly: you have to believe it is really going to happen, or your concentration will wander. It may wander to the woods, where every nocturnal furry animal seems hell bent on killing anything and everything smaller than itself; it may wander to the barn owls gliding silently by, sometimes no more than a yard or two from your face - these are sounds and glimpses you can enjoy some other time. Sea trout fishing requires dedication and 100 per cent concentration.
From late spring until late summer and often into autumn, sea trout in low clear rivers lie close to their daytime resting places, and for the most part those places are on the deep-water side of bends in the river. Most lies are either hard against the bank, where trees provide extra shading, or they are up against undercuts or rock ledges or on the litter-strewn bed of very deep pools, particularly in narrow gorges.
The easiest lies to find are those against the bank: just look for trees - the green ovals in the picture above are not only good places to try when sea trout are running up river but they are also likely resting lies. Water about a metre (3ft) deep is always worth a try, as it's not too difficult to present a fly quite close to the riverbank and at the same time close to the riverbed. Simply cast across and slightly downstream so that your fly sinks as it moves from the water's edge towards midstream. If a sea trout sees your fly it may well follow the fly more than half-way across the river before either taking it or turning back to its lie. If the sea trout nips the fly and continues swimming across stream with it in its jaws, don't expect a violent jerk on the line; it won't happen. Look for any subtle lift or fall of the line as it arcs down from your rod tip to the water's surface. Strike immediately if you see, feel or sense something unusual.
Of course, if a sea trout takes the fly and then turns back towards its lie you will feel a strong tug, and all you need to do is hang on tight and the fish will hook itself. In low-water summers when the river drifts lazily, violent takes are far from the norm.
A floating line or, if you prefer, an intermediate line is all you need for this kind of fishing, but if the river is running higher than summer normal a sinking poly leader can help get your fly down a bit deeper. Weighted flies also help in this respect.
If the river is well up but clear, even a heavy fly and a sink tip (or even a fast sinking line) may not be enough to get the fly down as deep as you need it before the current sweeps it away from the target area. Our solution to this problem is very simple: instead of casting down and across river we cast upstream, landing the fly (or flies if you use a team of two or three) several metres upstream of the target area. Let the fly sink in a 'dead drift' until it reaches the target area, and then retrieve line to bring your fly to life, drawing it slowly away from the bank and towards mid stream.
With this upstream and across technique, you can use a floating line or a sink tip and a weighted fly to get down deep very quickly: this is crucial when sea trout are not showing (by leaping and splashing on the surface). In unsettled weather, getting your flies down deep can make all the difference between a night to remember and a total blank.
When fishing in very deep gorges, we use full sinking lines and we cast very large flies upstream and across, drifting them downstream and, as the flies come alongside us, making a steady (non jerky) retrieve that is just fast enough to avoid hooking the riverbed. Naturally, you will only know that you are getting close to the riverbed if you catch either a sea trout or some of the debris on the bed of the river. Losing the occasional fly is nothing to worry about: it tells you that you are fishing deep enough and so maximising your chances of catching one of those monster sea trout that flyfisher's dream of.
By no means a monster, but the beautiful sea trout pictured here was hooked in deep water at a time when no sea trout were leaping and splashing: a deeply sunk fly was crucial to success.
Early in the evening a small fly and a fast retrieve often works very well, but as the light fades and even a sea trout has more difficulty seeing the fly we recommend a change in tactics. Switch to a progressively larger fly and retrieve more slowly. On the darkest of nights you may need a very large tube fly and the slowest retrieve that avoids getting hooked on riverbed debris or rocks. If even your largest fly provokes no response it may be that the sea trout simply can't see the fly; then it is time to switch to a surface lure or wake fly. Cast your surface lure across the belly of a deep pool and retrieve slowly but steadily; if a fish leaps at the fly, tighten only when it dives down.
Sea trout are fish... until hooked, then they behave more like birds. The sight of a large sea trout leaping well clear of the water is awesome, and if the hook is not set before the fish leaves the water the chances are it will be shaken free before the splash down. Strike quickly when you get a take, and strike firmly so that the hook is well and truly set. Then beware of putting too much pressure on a fish that you cannot see: it might even be in the air, at which time there is no water resistance to absorb the shock of its shaking head. A fast-action rod is a major disadvantage at such times, which is why we prefer and strongly recommend a middle-and-top action rod for sea trout fishing.
Unlike salmon, sea trout do not have wristy tails, so its usually impossible to lift a sea trout out of the water by its tail. (In any case this is not recommended if you intend returning the fish alive to the river, as its internal organs can be damaged by such handling.) Instead, place one hand on top of the sea trout and turn it upside down; it will not thrash about when held this way, and so if you intend returning it to the river you can simply unhook it while keeping the fish submerged. We use scissor-pliers or forceps for this purpose, and hooks and fingers in close proximity in the dark are not a good idea. Once it is unhooked, simply turn the sea trout upright and hold it with the head facing the current until it swims away; you can be confident that the probability of your fish surviving to spawn is not going to be significantly affected by its being caught and returned in this way. (A small proportion of sea trout die from accidents, predation or disease in river before they can spawn, and typically this is no more that 15 per cent; with careful handling and speedy release your sea trout is very likely indeed to go on to add to future stocks of sea trout in the river.
If you intend to take a sea trout out of the river, the safest way to do so is to net it, taking the fish while still in the net out onto the bank for a quick photograph and straight back into the water. If it is you intention to take it for the pot, the best advice is to despatch it immediately, while it is still in the net and you are still in the river.
In many rivers, sea trout stocks are so depleted that there is not a harvestable surplus, and only by catch-and-release can we maintain stock levels. This is certainly true in the rivers of Britain and Ireland in respect of large sea trout, a component of the run that has suffered serious decline in the past thirty years or so. Large sea trout should, in our opinion, always be released, as their genes are so important to the survival of the strain of sea trout that have a tendency to be long lived and/or fast growing. (Like old chickens, old sea trout are not the best to eat!)
There are many more techniques and tactics that, selected to suit the location and conditions, can take a lot of the luck out of sea trout fishing. While the average flyfisher catches typically just two or three sea trout in a season, those in the know can average more than that per night. Why settle for average when the average performance is so disappointing? There is no reason for suffering blank after blank, and with this basic introductory guide you should get to be to well above average even in your first season of sea trout fishing.
There's a wealth of detailed information on sea trout fishing techniques (as well as trout and salmon tactics and techniques) in Pat O'Reilly's book A Flyfisher's Guide to the Teifi Valley, which is based on 40 years of practical experience of this world-famous sea trout river as well as many other great sea trout rivers in Britain, Ireland and further afield. Certainly if you intend visiting the River Teifi in West Wales you are strongly urged to buy and read a copy beforehand.
If you have found this information helpful, please consider helping to keep First Nature online by making a small donation towards the web hosting and internet costs.
Any donations over and above the essential running costs will help support the conservation work of Plantlife, the Rivers Trust and charitable botanic gardens - as do author royalties and publisher proceeds from books by Pat and Sue.