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Rating depth structure for lake trout.
Recent public catches load as you reach this section.
338-acre lake in Thunder Bay District, Ontario. The lake tops out around 341 ft. Bathymetry on this water is estimated from its real outline and maximum depth. Use it to shortlist water, then verify with your electronics — and never navigate by it. Every species below gets its seasonal read from the same numbers driving the chart.
Coubran Lake maps at 338 acres behind 5.7 miles of shoreline. With a shoreline index of 2.2, this water is all arms and coves — edge habitat well beyond its acreage. 17% of the surface is littoral (under ~15 ft), per the model — cover, weeds and forage water. The basin spans about 2.1 mi end to end and 0.5 mi across at its widest. It sits in Thunder Bay District. Seeley Lake sits 3 mi southeast — the closest neighbouring chart.
When the water first warms, brook trout slide up into 2 to 15 ft. By summer they slide out to 10 to 30 ft, and by winter most fish are in 3 to 20 ft. If you only fish one area, make it Shallow bay flat: a feeding flat around 6 ft that scores good in spring. In summer the feeding windows fall in early morning and the evening. Keep a small spoon fished deep or a trolled lake-clear wobbler + worm rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 15 ft | dawn & dusk | Shallow bay flat (6 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 10 to 30 ft | dawn & dusk | open water | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 2 to 15 ft | midday & dawn | open water | Small spoon (orange), Spinner |
| Winter | 3 to 20 ft | dawn | Shallow bay flat (6 ft) | Small jigging spoon, Tungsten jig + plastic |
Early season lake trout use the shallows, holding in 10 to 40 ft. Expect a summer slide to 50 to 120 ft, then a winter hold in 20 to 80 ft. In summer the feeding windows fall in early morning. Tie on a white tube jig (deep) or a magnum spoon on downrigger and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 10 to 40 ft | dawn & dusk | open water | Casting spoon over shoals, Jerkbait (shallow) |
| Summer | 50 to 120 ft | dawn | open water | White tube jig (deep), Magnum spoon on downrigger |
| Fall | 10 to 50 ft | dusk & dawn | open water | Heavy casting spoon, Jigging rap over reefs |
| Winter | 20 to 80 ft | dawn | open water | White tube jig, Airplane jig |
Early season burbot use the shallows, holding in 25 to 70 ft. Expect a summer slide to 50 to 120 ft, then a winter hold in 15 to 60 ft. In summer the feeding windows fall in after dark and midday. Tie on a heavy jig + cut bait and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 25 to 70 ft | night & dusk | open water | Glow jigging spoon + cut bait, Rattle bait (dark) |
| Summer | 50 to 120 ft | night & midday | open water | Heavy jig + cut bait |
| Fall | 30 to 80 ft | night & dusk | open water | Glow spoon + minnow head, Blade bait (slow) |
| Winter | 15 to 60 ft | night & dusk | open water | Glow tungsten + cut bait, Rattle spoon + minnow head |
Count 6 structure marks on this chart. The deepest, Deep basin, sits near 290 ft.
Season dates, license requirements, and size and bag limits for Ontario waters are set by the Ontario fishing regulations (FMZ summary) — and special regulations can apply to Coubran Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Coubran Lake is about 341 ft (104 m) deep at its deepest point. The contours here are modeled from the water's real shape and maximum depth, so treat them as a rough guide.
Anglers target brook trout, lake trout, burbot on Coubran Lake.
Shallow bay flat is the top-rated area: a feeding flat in about 6 ft of water that rates good for brook trout in spring. Open the map above to see every rated spot for each species and season.
For brook trout, 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 Coubran Lake is regulated by the Ontario fishing regulations (FMZ summary). Check the official Ontario regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Seeley Lake 3 mi · Foxtrap Lake 12 mi · Campcot Lake 15 mi · Killala Lake 16 mi · Santoy Lake 19 mi · Gowan Lake 20 mi · Eric Lake 20 mi · Diablo Lake 20 mi · Fishnet Lake 21 mi · Box Lake 21 mi · Cairngorm Lake 23 mi · Esker Lake 24 mi
See how Coubran Lake stacks up: best lake trout lakes in Ontario · best brook trout lakes in Ontario · best burbot lakes in Ontario
More water nearby: Thunder Bay District fishing maps (662 charts). Browse all Ontario fishing maps. See every water on DepthScout. 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.