Sign inSign up free Sign inSign up free Sign inSign up freeSalt water depth chart
Today's read
Recent public catches load as you reach this section.
76,112-acre Lough Swilly. Outer 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 outer trip-scale survey reach of Lough Swilly, retaining only official survey-backed seabed cells that pass the Ireland release gates. The water tops out around 174 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. The season-by-season read for each species follows, from the map's own numbers.
The drawn water covers 76,220 acres wrapped in 82.7 miles of bank, broken up by 2 islands. With a 2.1 development index there's bank structure worth casting at, in moderation. About 3% of the surface sits shallower than 15 ft — that's the weed-and-bait zone. Call it 18.4 mi long by 17.4 mi wide at the broadest reach. Mulroy Bay - Outer sits 7 mi southwest — the closest neighbouring chart.
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 |
|---|---|---|
| Bass (European Seabass) | official species listing | — |
| Mackerel (Atlantic Mackerel) | official species listing | — |
| Herring (Atlantic Herring) | official species listing | — |
| Whiting (Whiting) | official species listing | — |
| Flounder (European Flounder) | official species listing | — |
| Plaice (European Plaice) | official species listing | — |
| Sole (Common Sole) | official species listing | — |
| Thornback ray (Thornback Ray) | official species listing | — |
| Thick-lipped grey mullet (Thick-lipped Grey Mullet) | official species listing | — |
| Garfish (Garfish) | official species listing | — |
| Sea trout (Sea Trout) | official species listing | — |
Official species-evidence source.
Spring european seabass on Lough Swilly - Outer hold shallow, usually 3 to 25 ft. They move out to 2 to 30 ft in summer and finish the year down in 10 to 55 ft. Put Shoreline point first on the milk run — a point near 12 ft that grades good for fall. The feeding windows run early morning and the evening. The summer box starts with a surface lure or a paddle-tail soft plastic.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 25 ft | dawn & dusk | Shoreline point (12 ft) | Paddle-tail soft plastic, Shallow minnow plug |
| Summer | 2 to 30 ft | dawn & dusk | Shoreline point (12 ft) | Surface lure, Paddle-tail soft plastic |
| Fall | 4 to 40 ft | dawn & dusk | Shoreline point (12 ft) | Slim metal lure, Minnow plug |
| Winter | 10 to 55 ft | midday | open water | Slow soft-plastic shad, Suspending minnow |
Spring puts atlantic mackerel in skinny water — 5 to 45 ft is the zone. Warm water sends them out to 15 to 80 ft; cold water stacks them in 30 to 120 ft. INFOMAR measured current seam is the standout, a current seam at roughly 78 ft, rated good for summer atlantic mackerel. Plan around early morning and the evening in the warm months. A feather rig or a small vertical jig covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 45 ft | dawn & dusk | Shoreline point (12 ft) | Mackerel feather rig, Small silver jig |
| Summer | 15 to 80 ft | dawn & dusk | INFOMAR measured current seam (78 ft) | Feather rig, Small vertical jig |
| Fall | 10 to 65 ft | dawn & dusk | INFOMAR measured current seam (78 ft) | Compact silver jig, Sparse feather rig |
| Winter | 30 to 120 ft | midday | Sharp break (85 ft) | Small deep jig |
Spring atlantic herring on Lough Swilly - Outer hold shallow, usually 5 to 25 ft. They move out to 15 to 50 ft in summer and finish the year down in 20 to 60 ft. Put Shoreline point first on the milk run — a point near 12 ft that grades good for spring. The feeding windows run early morning and the evening. The summer box starts with a herring feather rig or a small silver jig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 25 ft | dawn & dusk | Shoreline point (12 ft) | Small herring feather rig, Micro jig rig |
| Summer | 15 to 50 ft | dawn & dusk | open water | Herring feather rig, Small silver jig |
| Fall | 10 to 40 ft | dawn & dusk | open water | Small feather rig, Compact silver spoon |
| Winter | 20 to 60 ft | midday | open water | Small silver jig, Sparse feather rig |
Come spring, look for whiting tight to the bank in 15 to 55 ft. They move out to 20 to 70 ft in summer and finish the year down in 15 to 70 ft. If you only fish one area, make it INFOMAR measured current seam: a current seam around 78 ft that scores good in summer. Best bite is early morning. A small vertical jig is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 15 to 55 ft | dawn & dusk | open water | Small silver jig, Two-hook feather rig |
| Summer | 20 to 70 ft | dawn | INFOMAR measured current seam (78 ft) | Small vertical jig |
| Fall | 10 to 60 ft | dusk | open water | Small silver jig, Sparse feather rig |
| Winter | 15 to 70 ft | dusk | open water | Compact vertical jig |
Spring puts european flounder in skinny water — 5 to 25 ft is the zone. Warm water sends them out to 6 to 35 ft; cold water stacks them in 15 to 50 ft. Feeding flat is the standout, a feeding flat at roughly 37 ft, rated good for summer european flounder. Plan around early morning and the evening in the warm months. A bottom jig with spinner blade covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 25 ft | dusk | open water | Small bucktail dragged on bottom |
| Summer | 6 to 35 ft | dawn & dusk | Feeding flat (37 ft) | Bottom jig with spinner blade |
| Fall | 8 to 40 ft | dusk | Feeding flat (37 ft) | Compact bottom jig |
| Winter | 15 to 50 ft | midday | Feeding flat (37 ft) | Small bottom jig |
Come spring, look for european plaice tight to the bank in 8 to 35 ft. They move out to 6 to 40 ft in summer and finish the year down in 25 to 80 ft. If you only fish one area, make it Feeding flat: a feeding flat around 37 ft that scores prime in summer. Best bite is early morning and the evening. A light spooned bottom rig or a beaded trace is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 35 ft | dusk | Feeding flat (37 ft) | Beaded flowing trace |
| Summer | 6 to 40 ft | dawn & dusk | Feeding flat (37 ft) | Light spooned bottom rig, Beaded trace |
| Fall | 10 to 50 ft | dusk | Feeding flat (37 ft) | Beaded bottom trace |
| Winter | 25 to 80 ft | midday | open water |
Lough Swilly - Outer also holds common sole (3 to 30 ft in summer), thornback ray (10 to 65 ft in summer), thick-lipped grey mullet (1 to 18 ft in summer), garfish (2 to 20 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.
The chart marks 7 structure features on Lough Swilly - Outer; the deepest is Deepest basin at about 174 ft.
The complete Marine Institute Fishing Ports layer returned no port point inside this operational section. DepthScout does not substitute a nearby road, beach or community slipway as verified public fishing access; confirm legal access, parking, tides and local restrictions before visiting.
Private land and private launches need the owner's permission — please ask first.
Season dates, license requirements, and size and bag limits for Ireland waters are set by the Inland Fisheries Ireland (current sea-angling regulations) — and special regulations can apply to Lough Swilly - Outer specifically, so confirm the current rules before you fish. Check the current national and water-specific rules before every trip, including bass measures, the 2026 recreational pollack controls, salmon and sea-trout licences and river-specific status, protected areas, harbour directions, private land and local signs. A mapped fishing port or measured seabed feature is not permission to fish, park, launch or enter a working harbour.
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 Swilly - Outer is about 174 ft (53 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 european seabass, atlantic mackerel, atlantic herring, whiting, european flounder, european plaice, common sole, thornback ray, thick-lipped grey mullet, garfish, sea trout roster for Lough Swilly - Outer. 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.
Feeding flat is the top-rated area: a feeding flat in about 37 ft of water that rates prime for european plaice in summer. The interactive chart above rates every spot for each species and season.
For european seabass, 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 Swilly - Outer is regulated by the Inland Fisheries Ireland (current sea-angling regulations). Check the official Ireland regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Mulroy Bay - Outer 7 mi · Lough Foyle - Inner 11 mi, IRL/UK · Lough Swilly - Middle 14 mi · Sheephaven Bay - East 15 mi · Mulroy Bay - Inner 17 mi · Lough Foyle - Middle 22 mi, IRL/UK · Lough Foyle - Outer 24 mi, IRL/UK · Sheephaven Bay - West 31 mi · The Rosses and Gweedore Bay - Outer Islands 43 mi · Gweebarra Bay - Outer 51 mi · Loch Conailbhe 54 mi, UK · Donegal Bay - Central West North 58 mi
See how Lough Swilly - Outer stacks up: best sea trout lakes in Ireland · best atlantic herring lakes in Ireland · best european flounder lakes in Ireland · best garfish 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.