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28,419-acre Iroise Sea. Middle 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 middle west 4 angler-scale survey window. The water tops out around 151 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. Every species below gets its seasonal read from the same numbers driving the chart.
Drawn out, this is 28,414 acres of water rimmed by 55.6 miles of bank. With a shoreline index of 2.4, this water is all arms and coves — edge habitat well beyond its acreage. 30% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Figure 10.9 mi of water from one end to the other, 9.8 mi at the beam. Closest neighbour on DepthScout: Rade de Brest - South Central, 1 mi south of here.
Iroise Sea — Middle West 4, France : carte SHOM officielle jusqu’à 46 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.
The spring pattern is a shallow one: european seabass in 3 to 25 ft. As the season builds they drop to 2 to 30 ft, wintering in 10 to 55 ft. Top water on the chart: Shoreline point, a point in the 8 ft range, good in fall. Time it for early morning and the evening. Summer baits: a surface lure or a paddle-tail soft plastic gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 25 ft | dawn & dusk | Shoreline point (8 ft) | Paddle-tail soft plastic, Shallow minnow plug |
| Summer | 2 to 30 ft | dawn & dusk | Shoreline point (8 ft) | Surface lure, Paddle-tail soft plastic |
| Fall | 4 to 40 ft | dawn & dusk | Shoreline point (8 ft) | Slim metal lure, Minnow plug |
| Winter | 10 to 55 ft | midday | open water | Slow soft-plastic shad, Suspending minnow |
When the water first warms, atlantic mackerel slide up into 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. If you only fish one area, make it SHOM-grid current seam: a current seam around 60 ft that scores prime in fall. In summer the feeding windows fall in early morning and the evening. Keep a feather rig or a small vertical jig rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 45 ft | dawn & dusk | Shoreline point (8 ft) | Mackerel feather rig, Small silver jig |
| Summer | 15 to 80 ft | dawn & dusk | SHOM-grid current seam (60 ft) | Feather rig, Small vertical jig |
| Fall | 10 to 65 ft | dawn & dusk | SHOM-grid current seam (60 ft) | Compact silver jig, Sparse feather rig |
| Winter | 30 to 120 ft | midday | Sharp break (126 ft) | Small deep jig |
Spring atlantic pollock on Iroise Sea - Middle West 4 hold shallow, usually 8 to 100 ft. By summer they slide out to 12 to 150 ft, and by winter most fish are in 24 to 151 ft. The chart's best answer is Sharp break — drop-off, 126 ft, prime for winter. Prime time lands in early morning and the evening. The summer box starts with a surface plug or a baitfish swimbait.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 8 to 100 ft | dawn & dusk | Rock reef (3 ft) | Sandeel-pattern lure, Soft-plastic shad |
| Summer | 12 to 150 ft | dawn & dusk | Shoreline point (8 ft) | Surface plug, Baitfish swimbait |
| Fall | 14 to 151 ft | dawn | Rock reef (3 ft) | Metal jig, Minnow plug |
| Winter | 24 to 151 ft | midday | Sharp break (126 ft) | Slow metal jig, Weighted soft plastic |
The spring pattern is a shallow one: saithe (coalfish) in 14 to 151 ft. The depth story barely changes: 15 to 151 ft through summer, 21 to 151 ft in winter. Top water on the chart: SHOM-grid current seam, a current seam in the 60 ft range, prime in spring. Time it for early morning and the evening. Summer baits: a speed jig or a heavy paddletail gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 14 to 151 ft | dawn & dusk | SHOM-grid current seam (60 ft) | Slim metal jig, Paddletail |
| Summer | 15 to 151 ft | dawn & dusk | Sharp break (126 ft) | Speed jig, Heavy paddletail |
| Fall | 14 to 151 ft | dawn & dusk | SHOM-grid current seam (60 ft) | Metal jig, Baitfish swimbait |
| Winter | 21 to 151 ft | midday | Deepest basin (145 ft) | Heavy vertical jig |
Spring atlantic cod on Iroise Sea - Middle West 4 hold shallow, usually 20 to 100 ft. By summer they slide out to 38 to 151 ft, and by winter most fish are in 34 to 151 ft. The chart's best answer is Deepest basin — deep basin, 145 ft, prime for winter. Prime time lands in early morning. The summer box starts with a heavy metal jig or a large soft-plastic jig.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 20 to 100 ft | dawn | Rock reef (3 ft) | Diamond jig, Heavy bucktail |
| Summer | 38 to 151 ft | dawn | Deepest basin (145 ft) | Heavy metal jig, Large soft-plastic jig |
| Fall | 25 to 140 ft | dawn | Rock reef (3 ft) | Diamond jig, Bucktail with teaser |
| Winter | 34 to 151 ft | midday | Deepest basin (145 ft) | Heavy vertical jig |
The spring pattern is a shallow one: ling in 27 to 151 ft. The depth story barely changes: 25 to 151 ft through summer, 28 to 151 ft in winter. Top water on the chart: Sharp break, a drop-off in the 126 ft range, prime in spring. Time it for midday. Summer baits: a heavy vertical jig gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 27 to 151 ft | midday | Sharp break (126 ft) | Heavy metal jig, Large soft-plastic jig |
| Summer | 25 to 151 ft | midday | Sharp break (126 ft) | Heavy vertical jig |
| Fall | 26 to 151 ft | midday | Sharp break (126 ft) | Long metal jig |
| Winter | 28 to 151 ft | midday | Deepest basin (145 ft) | Heavy deep jig |
Iroise Sea - Middle 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 - Middle West 4 carries 9 mapped structure features, topping out (or rather bottoming out) at Deepest basin, about 145 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 - Middle 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 - Middle West 4 is about 151 ft (46 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 - Middle 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 60 ft of water that rates prime for atlantic mackerel in fall. The map above holds the full rated-spot list for every 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 - Middle 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.
Rade de Brest - South Central 1 mi · Rade de Brest - South West 6 mi · Iroise Sea - Middle West 5 7 mi · Rade de Brest - South East 10 mi · Iroise Sea - Middle West 3 11 mi · Iroise Sea - South West 4 12 mi · Iroise Sea - South West 5 14 mi · Iroise Sea - South West 3 16 mi · Iroise Sea - Middle West 2 20 mi · Baie de Douarnenez - South Central 24 mi · Iroise Sea - North West 3 24 mi · Iroise Sea - South West 2 24 mi
See how Iroise Sea - Middle 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.