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9,845-acre Lough Foyle. Inner saltwater fishing map with official INFOMAR survey bathymetry, measured-cell fishing spots, official fish evidence, seasonal forage guidance, access context and current-rule links. The inner trip-scale survey reach of Lough Foyle, retaining only official survey-backed seabed cells that pass the Ireland release gates. The water tops out around 67 ft. The depth chart comes from INFOMAR (Geological Survey Ireland and Marine Institute) bathymetric survey data, so the contours are survey-derived rather than computer-modeled. What the data behind the map says about each species, season by season:
The outline encloses 9,848 acres, worked by 44.3 miles of shoreline, with 2 islands in the mix. An index of 3.2 puts the bank firmly in maze territory: point after pocket after cove, every one a casting target. The shallow band under 15 ft claims about 22% of the surface — that's where the groceries are. Figure 12.5 mi of water from one end to the other, 3.8 mi at the beam. If the bite dies, Lough Swilly - Middle is 4 mi to the south.
Marine Institute spawning, nursery, observation and range layers support the principal surveyed pelagic and groundfish. IFI's national and regional sea-angling publications support additional habitat-compatible recreational targets. This is occurrence and search guidance, not equal abundance, a section-level population estimate or a promised catch. The roster may combine exact-water monitoring with habitat-filtered official regional evidence; it does not imply that every species is equally abundant throughout the mapped section.
| Species | Evidence basis | Count / date |
|---|---|---|
| Mackerel (Atlantic Mackerel) | official species listing | — |
| Pollack (Atlantic Pollock) | official species listing | — |
| Coalfish (Saithe (Coalfish)) | official species listing | — |
| Haddock (Haddock) | official species listing | — |
| Whiting (Whiting) | official species listing | — |
| Cod (Atlantic Cod) | official species listing | — |
| Plaice (European Plaice) | official species listing | — |
| Flounder (European Flounder) | official species listing | — |
| Thornback ray (Thornback Ray) | official species listing | — |
| Sea trout (Sea Trout) | official species listing | — |
Official species-evidence source.
Start shallow in spring: atlantic mackerel sit in 5 to 45 ft that time of year. Warm water sends them out to 13 to 67 ft; cold water stacks them in 17 to 67 ft. Top water on the chart: Deepest basin, a deep basin in the 65 ft range, prime in summer. Fish it in early morning and the evening and you'll meet the bite. Throw a feather rig or a small vertical jig until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 45 ft | dawn & dusk | INFOMAR measured current seam (30 ft) | Mackerel feather rig, Small silver jig |
| Summer | 13 to 67 ft | dawn & dusk | Deepest basin (65 ft) | Feather rig, Small vertical jig |
| Fall | 10 to 65 ft | dawn & dusk | INFOMAR measured current seam (30 ft) | Compact silver jig, Sparse feather rig |
| Winter | 17 to 67 ft | midday | Deepest basin (65 ft) | Small deep jig |
The spring pattern is a shallow one: atlantic pollock in 5 to 67 ft. The depth story barely changes: 5 to 67 ft through summer, 11 to 67 ft in winter. Top water on the chart: Shoreline point, a point in the 12 ft range, prime in summer. Time it for early morning and the evening. Summer baits: a surface plug or a baitfish swimbait gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 67 ft | dawn & dusk | Shoreline point (12 ft) | Sandeel-pattern lure, Soft-plastic shad |
| Summer | 5 to 67 ft | dawn & dusk | Shoreline point (12 ft) | Surface plug, Baitfish swimbait |
| Fall | 6 to 67 ft | dawn | Shoreline point (12 ft) | Metal jig, Minnow plug |
| Winter | 11 to 67 ft | midday | Sharp break (5 ft) | Slow metal jig, Weighted soft plastic |
Come spring, look for saithe (coalfish) tight to the bank in 6 to 67 ft. Through summer count on 6 to 67 ft; the winter hold is 9 to 67 ft. If you only fish one area, make it INFOMAR measured current seam: a current seam around 30 ft that scores prime in spring. Best bite is early morning and the evening. A speed jig or a heavy paddletail is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 6 to 67 ft | dawn & dusk | INFOMAR measured current seam (30 ft) | Slim metal jig, Paddletail |
| Summer | 6 to 67 ft | dawn & dusk | Sharp break (5 ft) | Speed jig, Heavy paddletail |
| Fall | 6 to 67 ft | dawn & dusk | INFOMAR measured current seam (30 ft) | Metal jig, Baitfish swimbait |
| Winter | 9 to 67 ft | midday | Deepest basin (65 ft) | Heavy vertical jig |
Spring haddock on Lough Foyle - Inner hold shallow, usually 11 to 67 ft. Depth-wise the year is flat: 13 to 67 ft in summer, 12 to 67 ft once it turns cold. Put Deepest basin first on the milk run — a deep basin near 65 ft that grades prime for spring. The feeding windows run early morning. The summer box starts with a compact metal jig or a bottom rig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 11 to 67 ft | dawn | Deepest basin (65 ft) | Small bottom jig, Beaded trace |
| Summer | 13 to 67 ft | dawn | Deepest basin (65 ft) | Compact metal jig, Bottom rig |
| Fall | 12 to 67 ft | midday | Feeding flat (20 ft) | Small vertical jig |
| Winter | 12 to 67 ft | midday | Deepest basin (65 ft) | Deep bottom jig |
Spring whiting on Lough Foyle - Inner hold shallow, usually 15 to 55 ft. They move out to 19 to 67 ft in summer and finish the year down in 14 to 67 ft. Put INFOMAR measured channel edge first on the milk run — a channel edge near 37 ft that grades prime for spring. The feeding windows run early morning. The summer box starts with a small vertical jig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 15 to 55 ft | dawn & dusk | INFOMAR measured channel edge (37 ft) | Small silver jig, Two-hook feather rig |
| Summer | 19 to 67 ft | dawn | Deepest basin (65 ft) | Small vertical jig |
| Fall | 10 to 60 ft | dusk | INFOMAR measured channel edge (37 ft) | Small silver jig, Sparse feather rig |
| Winter | 14 to 67 ft | dusk | Deepest basin (65 ft) | Compact vertical jig |
The spring pattern is a shallow one: atlantic cod in 13 to 67 ft. The depth story barely changes: 17 to 67 ft through summer, 15 to 67 ft in winter. Top water on the chart: Deepest basin, a deep basin in the 65 ft range, prime in winter. Time it for early morning. Summer baits: a heavy metal jig or a large soft-plastic jig gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 13 to 67 ft | dawn | INFOMAR measured channel edge (37 ft) | Diamond jig, Heavy bucktail |
| Summer | 17 to 67 ft | dawn | Deepest basin (65 ft) | Heavy metal jig, Large soft-plastic jig |
| Fall | 12 to 67 ft | dawn | INFOMAR measured channel edge (37 ft) | Diamond jig, Bucktail with teaser |
| Winter | 15 to 67 ft | midday | Deepest basin (65 ft) | Heavy vertical jig |
Lough Foyle - Inner also holds european plaice (6 to 40 ft in summer), european flounder (6 to 35 ft in summer), thornback ray (10 to 65 ft in summer), sea trout (15 to 50 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Count 7 structure marks on this chart. The deepest, Deepest basin, sits near 65 ft.
Access data: Marine Institute — Fishing Ports. Confirm conditions and fees locally before you launch.
Season dates, license requirements, and size and bag limits for Ireland waters are set by the Loughs Agency and Inland Fisheries Ireland (cross-border rules) — and special regulations can apply to Lough Foyle - Inner specifically, so confirm the current rules before you fish. Lough Foyle and Carlingford Lough are cross-border fisheries. Check current Loughs Agency rules and permits together with the applicable Irish and Northern Irish sea-angling, salmon and sea-trout rules before fishing. Jurisdiction, protected areas, harbour directions and access can change within one trip-scale section; a DepthScout boundary or port lead is never legal permission.
Check the official Ireland fishing regulations →
Department of Climate, Energy and the Environment (2026 salmon and sea-trout status) →
Check special-area and water-specific rules →
Check official shore-access information →
Lough Foyle - Inner is about 67 ft (20 m) deep at its deepest point. The depth chart comes from INFOMAR (Geological Survey Ireland and Marine Institute) bathymetric survey data, so the contours are survey-derived rather than computer-modeled.
Official coastal monitoring from Marine Institute and Inland Fisheries Ireland informs the atlantic mackerel, atlantic pollock, saithe (coalfish), haddock, whiting, atlantic cod, european plaice, european flounder, thornback ray, sea trout roster for Lough Foyle - Inner. The mixed roster combines exact-water records where available with habitat-filtered regional evidence; not every species is documented at this exact water, and it is not a promise of equal abundance or a catch on a particular trip.
Deepest basin is the top-rated area: a deep basin in about 65 ft of water that rates prime for atlantic mackerel in summer. The map above holds the full rated-spot list for every species and season.
For atlantic mackerel, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Lough Foyle - Inner is regulated by the Loughs Agency and Inland Fisheries Ireland (cross-border rules). Check the official Ireland regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Lough Swilly - Middle 4 mi, IRL · Mulroy Bay - Inner 6 mi, IRL · Mulroy Bay - Outer 8 mi, IRL · Lough Swilly - Outer 11 mi, IRL · Lough Foyle - Middle 13 mi · Sheephaven Bay - East 18 mi, IRL · Lough Foyle - Outer 19 mi · Sheephaven Bay - West 34 mi, IRL · The Rosses and Gweedore Bay - Outer Islands 42 mi, IRL · Gweebarra Bay - Outer 48 mi, IRL · Donegal Bay - Central East 52 mi, IRL · Donegal Bay - Central West North 53 mi, IRL
See how Lough Foyle - Inner stacks up: best sea trout lakes in Ireland · best european flounder lakes in Ireland · best european plaice lakes in Ireland · best whiting lakes in Ireland
Browse all Ireland fishing maps. See every water on DepthScout. Bathymetry credit: INFOMAR (Geological Survey Ireland and Marine Institute) INFOMAR All Survey bathymetry mosaic (Source-survey vertical references retained in the INFOMAR All Survey mosaic; 100% measured, 0% source-interpolated). How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.