Lowland · Mixed · East / Meath

Nanny & Delvin Rivers

Nanny & Delvin Rivers terrain map

Two small east-coast rivers — the Nanny running through Duleek and Julianstown to the sea at Laytown, the Delvin reaching it near Balbriggan.

Fair · Sea Trout
Black & Silver Tube · 1-2 inch
Fairlive now
Decent — worth a look
River lifting fast on the rain. Wait for the rise to peak before settling on a beat.
65% confidence
What moved it
  • LevelProxyvia Boyne
  • Water temp14.0°C
  • ClarityVery colouredColouring up
Today's fly
BS
Black & Silver Tube1-2 inch
In deep pools and dark water, silhouette and contrast do the work colour cannot. A fly that reads as black against depth is enough. Fish it broadside, hold the swing, let it hang at the dangle — that is when the best fish take.
Conditions on the water
Proxy gauge
Level
Rising
Proxy
via Boyne
Water temp14.0°C
ClarityVery coloured
Weather26°C
WindSW 15 km/h
Pressure1020 hPa
Rain · recent0.0 mm
Rain · ahead0.3 mm

No gauge on this water — conditions are inferred from Boyne. The trend transfers, the absolute level does not.

Water temperature for Sea Trout
Ideal
14°C est.ideal 815°C
0°14°28°
How to fish it · for Sea Trout
When
From dusk into the first half of the night.
Where
Deeper pools and slower glides · hold water and current seams.
Method
Fish dark patterns on a sink-tip or lightly sunk line, especially near structure.
Kit
10 ft #6/7 rod, floating line with a sink-tip option, 8–10 lb fluoro tippet for the swing.
Why this works
Good — water temperature is working for you, but time of day is the limiting factor today.
Hatch timeline · todayPeak at 6am

Hatch predictions

Today's headline hatch shown — see all 9 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

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Evidence
Survey-backed · regionalHigh confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Updated 8 hours ago

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Daddy Long LegsHatch
2
3
2
Terrestrial BeetlesHatch
2
3
3
2
Blue Winged OliveHatch
1
2
2
2
2
1
Black MidgeHatch
1
2
2
2
2
2
2
2
2
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Sea Trout fly box
BS
Black & Silver TubeTop
1-2 inch · Tube
In deep pools and dark water, silhouette and contrast do the work colour cannot. A fly that reads as black against depth is enough. Fish it broadside, hold the swing, let it hang at the dangle — that is when the best fish take.
SF
Snake Fly (Black)
2-4 inch · Streamer
A mobile eel-like profile that undulates through deep pools — effective when sea trout are lying deep and not responding to conventional wets.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
About this water

Two small east-coast rivers — the Nanny running through Duleek and Julianstown to the sea at Laytown, the Delvin reaching it near Balbriggan. Each holds a stock of wild brown trout and takes a run of sea trout from late May into summer. The best of the Nanny's trout water is Julianstown up to above Balrath Bridge, fly-only above Bellewstown Bridge. Duleek Anglers and Drogheda & District Anglers hold most of the Nanny; the Delvin is largely riparian-owner water, so enquire locally.

Hatches & food

Two small limestone-based east-coast rivers with modest olive and sedge hatches for the resident trout; summer fishing pivots to flood-run sea trout taking sedges and terrestrials in the tidal lower reaches.

  • Mixed
Why this score · for Sea Trout
  • Temperature10028% weight
  • Flow5522% weight
  • Clarity4518% weight
  • Feeding Time2013% weight
  • Pressure857% weight
  • Insect activity5312% weight
Directions
Seasons & zones
  • Trout 15 February30 September

Sea trout: Variable seasonal (2026)

Related guides
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