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54,316-acre Iroise Sea. South West 4 France saltwater fishing map with official SHOM 100 m bathymetry, source-qualified fishing spots, official regional fish evidence, seasonal forage guidance, public shore-use context and current-rule links. The exposed Iroise Sea from Ushant through the Brest approaches, with reefs, islands and strong Atlantic tide races. This page covers the south west 4 angler-scale survey window. The water tops out around 130 ft. The depth chart comes from Shom (Service hydrographique et océanographique de la Marine) bathymetric survey data, so the contours are survey-derived rather than computer-modeled. Here's the year, species by species, as the scoring engine sees it.
Drawn out, this is 54,304 acres of water rimmed by 53.5 miles of bank. Index 1.6 on the shoreline: a few honest points and pockets, nothing labyrinthine. About 5% of the surface sits shallower than 15 ft — that's the weed-and-bait zone. End to end it runs roughly 12.3 mi, about 10.4 mi across. For a second option, Iroise Sea - South West 5 lies 7 mi east.
Iroise Sea — South West 4, France : carte SHOM officielle jusqu’à 40 m; spots pour bar commun, maquereau commun. Pour préparer la pêche, jamais pour naviguer. Les profondeurs et les points de structure proviennent de la grille bathymétrique officielle du Shom. Les données servent à préparer la pêche et ne doivent jamais être utilisées pour la navigation.
Regional occurrence supports a search target, not equal abundance, child-specific catch rate, retention permission or a promised catch. Current national, EU, regional, protected-area and species rules always control. 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 |
|---|---|---|
| bar commun (European Seabass) | official species listing | — |
| maquereau commun (Atlantic Mackerel) | official species listing | — |
| lieu jaune (Atlantic Pollock) | official species listing | — |
| lieu noir (Saithe (Coalfish)) | official species listing | — |
| cabillaud (Atlantic Cod) | official species listing | — |
| lingue (Ling) | official species listing | — |
| orphie (Garfish) | official species listing | — |
| barbue (Brill) | official species listing | — |
| raie bouclée (Thornback Ray) | official species listing | — |
| sole commune (Common Sole) | official species listing | — |
| mulet lippu (Thick-lipped Grey Mullet) | official species listing | — |
| mulet cabot (Flathead Grey Mullet) | official species listing | — |
| anguille européenne (European Eel) | official species listing | — |
Official species-evidence source.
Spring puts european seabass in skinny water — 3 to 25 ft is the zone. As the season builds they drop to 2 to 30 ft, wintering in 10 to 55 ft. Fall european seabass concentrate at Shoreline point, a good-rated point around 32 ft. Warm-month bites cluster around early morning and the evening. A surface lure or a paddle-tail soft plastic covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 25 ft | dawn & dusk | open water | Paddle-tail soft plastic, Shallow minnow plug |
| Summer | 2 to 30 ft | dawn & dusk | Shoreline point (32 ft) | Surface lure, Paddle-tail soft plastic |
| Fall | 4 to 40 ft | dawn & dusk | Shoreline point (32 ft) | Slim metal lure, Minnow plug |
| Winter | 10 to 55 ft | midday | SHOM-grid channel edge (65 ft) | Slow soft-plastic shad, Suspending minnow |
Spring atlantic mackerel on Iroise Sea - South West 4 hold shallow, usually 5 to 45 ft. By summer they slide out to 15 to 80 ft, and by winter most fish are in 30 to 120 ft. The chart's best answer is SHOM-grid current seam — current seam, 52 ft, prime for fall. Prime time lands in early morning and the evening. The summer box starts with a feather rig or a small vertical jig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 45 ft | dawn & dusk | Shoreline point (32 ft) | Mackerel feather rig, Small silver jig |
| Summer | 15 to 80 ft | dawn & dusk | Sharp break (70 ft) | Feather rig, Small vertical jig |
| Fall | 10 to 65 ft | dawn & dusk | SHOM-grid current seam (52 ft) | Compact silver jig, Sparse feather rig |
| Winter | 30 to 120 ft | midday | Deepest basin (130 ft) | Small deep jig |
When the water first warms, atlantic pollock slide up into 8 to 100 ft. By summer they slide out to 10 to 130 ft, and by winter most fish are in 21 to 130 ft. If you only fish one area, make it Shoreline point: a point around 32 ft that scores prime in summer. In summer the feeding windows fall in early morning and the evening. Keep a surface plug or a baitfish swimbait rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 100 ft | dawn & dusk | Rock reef (4 ft) | Sandeel-pattern lure, Soft-plastic shad |
| Summer | 10 to 130 ft | dawn & dusk | Shoreline point (32 ft) | Surface plug, Baitfish swimbait |
| Fall | 12 to 130 ft | dawn | Shoreline point (32 ft) | Metal jig, Minnow plug |
| Winter | 21 to 130 ft | midday | Sharp break (70 ft) | Slow metal jig, Weighted soft plastic |
Spring puts saithe (coalfish) in skinny water — 12 to 130 ft is the zone. Summer fish stay in 13 to 130 ft, and winter fish hold in 18 to 130 ft. Spring saithe (coalfish) concentrate at SHOM-grid current seam, a prime-rated current seam around 52 ft. Warm-month bites cluster around early morning and the evening. A speed jig or a heavy paddletail covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 12 to 130 ft | dawn & dusk | SHOM-grid current seam (52 ft) | Slim metal jig, Paddletail |
| Summer | 13 to 130 ft | dawn & dusk | Sharp break (70 ft) | Speed jig, Heavy paddletail |
| Fall | 12 to 130 ft | dawn & dusk | SHOM-grid current seam (52 ft) | Metal jig, Baitfish swimbait |
| Winter | 18 to 130 ft | midday | Deepest basin (130 ft) | Heavy vertical jig |
When the water first warms, atlantic cod slide up into 20 to 100 ft. By summer they slide out to 33 to 130 ft, and by winter most fish are in 30 to 130 ft. If you only fish one area, make it Deepest basin: a deep basin around 130 ft that scores prime in winter. In summer the feeding windows fall in early morning. Keep a heavy metal jig or a large soft-plastic jig rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 20 to 100 ft | dawn | Sharp break (70 ft) | Diamond jig, Heavy bucktail |
| Summer | 33 to 130 ft | dawn | Deepest basin (130 ft) | Heavy metal jig, Large soft-plastic jig |
| Fall | 23 to 130 ft | dawn | Rock reef (4 ft) | Diamond jig, Bucktail with teaser |
| Winter | 30 to 130 ft | midday | Deepest basin (130 ft) | Heavy vertical jig |
Spring puts ling in skinny water — 23 to 130 ft is the zone. Summer fish stay in 22 to 130 ft, and winter fish hold in 24 to 130 ft. Spring ling concentrate at Sharp break, a prime-rated drop-off around 70 ft. Warm-month bites cluster around midday. A heavy vertical jig covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 23 to 130 ft | midday | Sharp break (70 ft) | Heavy metal jig, Large soft-plastic jig |
| Summer | 22 to 130 ft | midday | Sharp break (70 ft) | Heavy vertical jig |
| Fall | 23 to 130 ft | midday | Sharp break (70 ft) | Long metal jig |
| Winter | 24 to 130 ft | midday | Deepest basin (130 ft) | Heavy deep jig |
Iroise Sea - South West 4 also holds garfish (2 to 20 ft in summer), brill (6 to 50 ft in summer), thornback ray (10 to 65 ft in summer), common sole (3 to 30 ft in summer), thick-lipped grey mullet (1 to 18 ft in summer), flathead grey mullet (1 to 22 ft in summer), european eel (6 to 28 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Iroise Sea - South West 4 carries 9 mapped structure features, topping out (or rather bottoming out) at Deepest basin, about 130 ft down.
Access data: European Environment Agency — 2025 Bathing Water Directive Sites (France). Confirm conditions and fees locally before you launch.
Season dates, license requirements, and size and bag limits for France waters are set by the Légifrance (current French recreational sea-fishing minimum sizes) — and special regulations can apply to Iroise Sea - South West 4 specifically, so confirm the current rules before you fish. French recreational sea-fishing rules combine current national and European species measures with façade, prefectural, marine-protected-area, harbour and local access controls. Check live minimum sizes, quotas, seasonal or method closures, marking requirements and any no-take zone before every trip. A SHOM contour, fishing-spot marker or designated bathing-water lead is planning context only and never permission to fish, retain a catch, park, launch or enter restricted shore or port property.
Check the official France fishing regulations →
French Ministry for Ecological Transition — recreational sea fishing →
Check special-area and water-specific rules →
Check official shore-access information →
Iroise Sea - South West 4 is about 130 ft (40 m) deep at its deepest point. The depth chart comes from Shom (Service hydrographique et océanographique de la Marine) bathymetric survey data, so the contours are survey-derived rather than computer-modeled.
Official coastal monitoring from Ifremer CGFS and coastal estuary monitoring regional survey evidence informs the european seabass, atlantic mackerel, atlantic pollock, saithe (coalfish), atlantic cod, ling, garfish, brill, thornback ray, common sole, thick-lipped grey mullet, flathead grey mullet, european eel roster for Iroise Sea - South West 4. 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.
SHOM-grid current seam is the top-rated area: a current seam in about 52 ft of water that rates prime for atlantic mackerel in fall. Scroll up to the map for the complete spot list by 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 Iroise Sea - South West 4 is regulated by the Légifrance (current French recreational sea-fishing minimum sizes). Check the official France regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Iroise Sea - South West 5 7 mi · Iroise Sea - South West 3 10 mi · Rade de Brest - South Central 11 mi · Rade de Brest - South West 11 mi · Baie de Douarnenez - South Central 12 mi · Iroise Sea - Middle West 4 12 mi · Iroise Sea - Middle West 5 13 mi · Rade de Brest - South East 13 mi · Iroise Sea - Middle West 3 14 mi · Baie de Douarnenez - South West 14 mi · Baie d’Audierne - North Central 18 mi · Iroise Sea - South West 2 20 mi
See how Iroise Sea - South West 4 stacks up: best garfish lakes in France · best european seabass lakes in France · best common sole lakes in France · best thick-lipped grey mullet lakes in France
Browse all France fishing maps. See every water on DepthScout. Bathymetry: published agency survey data. 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.