Sea Trout Fishing Advice for Anglers visiting the Teifi Valley

Over many years the River Teifi has gained a reputation as a first class sea trout river. Sea trout, or sewin as they are called in Wales, are migratory forms of our native brown trout. Typically 2500 to 5000 sewin are caught on the Teifi each year. The greatest numbers of fish, averaging a pound and a half, are present in the river from June until the end of the season (17th October). Larger sewin in the region of 6 lbs and upwards are encountered from late April or early May onwards.

Bernard Venables and Pat O'Reilly
David Williams fishing at Rhydygalfe

Sewin can be caught on spinner, worm or fly, depending on river conditions; however, there is broad agreement that the most exciting method of fishing for sewin is with a fly at night, and the vast majority of sea trout caught on Llandysul A A waters fall to a fly fished at dusk or in the dark. These brief notes cover a few basic techniques that should help you to get started.


There is no need to go to extra expense when tackling up for night fishing for sewin. Stillwater or river outfits (other than very light brook rods) can usually cope. If you are tackling up from scratch this is the sort of equipment which many local anglers have found serves them well:

Rod: 9' 6" to 10' 6" with an AFTM rating of between 6 and 9. The action should not be too fast. (A stiff rod with a very short flexible length of top joint will not absorb the shock of a leaping sea trout.)

Lines: floater, intermediate, and fast sink. You will probably make most use of the floater, so go for this type if you only buy one line. Double taper lines are preferred by some sea trout fishers because the thin running line of a weight forward is less easy to see in the dark. A white line will be more visible at night, and in low water conditions movement of the line can act as a useful indication of a 'take'.

Leader: Approximately 9' 6" of 6 to 12 lb breaking strain nylon. If you are new to night fishing check your leader frequently for wind knots which can seriously weaken the nylon.

Accessories: A stout landing net (if you use a net at all); and a priest (if you intend taking fish) and a reliable torch are essential.


Pat O'Reilly returning a 3lb sewin

Butcher, Alexandra, Haslam, Dunkeld, Dark Mackerel and Sweeney Todd all work well in clear water; Silver Doctor, Medicine and Teifi Terror are especially effective when there is a hint of colour in the water. Silver surface lures and dry sedges also catch sewin, especially when fished beneath overhanging trees or across the tail of a pool.

From such a list of fly patterns it is evident that many types of flies will succeed in catching fish, and every serious sewin angler seems to have his own favourite pattern. If you find this list confusing, here is a cast of flies which should bring a sewin to your net in a wide range of conditions:

Top dropper - Teal, Blue & Silver, size 8

Middle dropper: Mallard & Claret, size 8

Point: Butcher, size 10.

Above: Pat O'Reilly returns a 3lb sea trout to the Teifi in springtime, when daytime fishing can be very effective during dull weather or when the water is slightly coloured.


You need a 'Salmon and Migratory Trout' licence to fish for sewin; a Trout/Coarse fish licence will not do.

Which beats are best?

Most of the Llandysul Angling Association waters are suitable for night time sewin fishing, but there are a few dangerous spots, so do try to get local advice. The tackle shops at Llandysul (Alma Stores, Wind Street) and Lampeter (Alan Williams, 57 Bridge Street) are obvious places to start asking for this information.

Where and when should I start?

Wait for nightfall before beginning to fish, otherwise you are likely to disturb the sewin. It is also a good idea periodically to rest your water for ten minutes or so during the night. The tail of a pool is usually a productive spot as fish drop back to this position after dusk. Later in the night the whole pool can be searched methodically. Sooner or later you will encounter a shoal of sewin and the action will start. Sewin like to rest beneath overhanging trees, so give such spots an extra thorough searching.

Fishing methods

Ian McDonald with a 13lb sewin

The most widely used style of fishing is the down and across method. In deep water, a wet fly cast upstream and across can be more effective in getting the flies downdeep to where the sea trout are resting. This method often tempts a sewin or two on nights when all else fails.

There are times when sea trout will take a dry fly, even during the day, and this method works particularly well on tree-shaded reaches of the river. It is not a technique recommended for early in the year, but it comes into its own as the season advances. Dry fly fishing for sea trout can be very effective as the water fines off following an autumn spate.

Surface lures (large floating flies that leave a wake when dragged across the surface of the river) work well at night. Some anglers reserve this method for when 'all else is failing', but some superb sea trout can be caught this way - so much so that those in the know see this as a major tactic and at times by far the preferred method. Pool tails are traditionally the place where surface lures - also known as wake flies - are most commonly used; however, on very dark nights when the river is low, big sea trout will rise up from the riverbed of the deepest pools to seize a surface lure that disturbs the calm surface. (A traditionally fly at great depth on such nights would be invisible unless it happened by chance to pass tight in front of a sea trout's nose.)

Muddler Minnows are effective sea trout surface lures; alternatively simple but very effective wake flies can be make by tying a piece of Ethafoam to a hook. (You can always add a hackle just for 'looks'!)

The sewin shown above, caught by club member Mr Ian McDonald, weighed over 13lbs.

Weather conditions

For best fishing with the fly, the night needs to be warm and overcast, and the river at a fairly low level. Then a floating or an intermediate line would normally be used. If the river is running high or the air temperature is much colder than that of the water, a sunk line would be preferable. Then larger and brighter flies should be fished slowly near the river bed.

When the river is in full spate spinning tactics can best be employed. Suitable lures are Mepps spoons in sizes 1-3, small Devons, Quill minnows, Toby lures and Irish minnows. A worm, trotted using a fly rod and line, is a very popular and successful method of fishing for sewin when the river is heavily coloured.


Night time sea trout fishing can present extra hazards over and above those of day time fishing; so you must be extra careful. If you intend to wade during the night, visit the spot you intend to fish during daylight hours and make sure you are familiar with that particular stretch of water. If you are going fishing alone then inform someone of where you intend to fish and what time you expect to be back. For more details, see our Safety Guide.