Lake depth chart
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1,295-acre lake in Thunder Bay District, Ontario. The lake tops out around 62 ft. This chart interpolates between a real shoreline and a known maximum depth. It will point you at likely water, but it is not a navigation product. Below is the species-by-species picture, pulled from the same data the map uses.
Isobel Lake maps at 1,302 acres behind 30.5 miles of shoreline — 2 islands included. A development index of 6 means a maze of bays and points: far more casting targets than a round bowl of the same size. 80% of the surface is littoral (under ~15 ft), per the model — cover, weeds and forage water. Call it 6.3 mi long by 1.7 mi wide at the broadest reach. Thunder Bay District claims this one. Lyons Lake sits 3 mi southwest — the closest neighbouring chart.
Spring puts lake whitefish in skinny water — 15 to 45 ft is the zone. Warm water sends them out to 19 to 62 ft; cold water stacks them in 19 to 62 ft. Deep basin is the standout, a deep basin at roughly 53 ft, rated prime for summer lake whitefish. Plan around early morning in the warm months. A blade bait vertical or a small jigging spoon covers the summer program.
Depth note: when a documented seasonal range extends below this chart, the table shows the deepest mapped working water, not a verified holding depth.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 15 to 45 ft | midday & dawn | Break off the point (28 ft) | Small jig + waxworm, Blade bait (small) |
| Summer | 19 to 62 ft chart-limited; documented 40 to 90 ft | dawn | Deep basin (53 ft) | Blade bait vertical, Small jigging spoon |
| Fall | 8 to 30 ft | dusk | Break off the point (28 ft) | Small spoon (gold), Jig + plastic larva |
| Winter | 19 to 62 ft chart-limited; documented 25 to 70 ft | midday & dawn | Deep basin (53 ft) | Jigging spoon + bead chain, Tungsten jig + waxie |
Start shallow in spring: walleye sit in 4 to 15 ft that time of year. Summer pushes them deeper, 15 to 35 ft, and winter fish settle into 20 to 40 ft. The spot to know is Break off the point, a drop-off in about 28 ft of water that rates prime for walleye in fall. Warm-month bites cluster around the evening and early morning. Throw a crawler harness on bottom bouncer or a deep crankbait (trolled) until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 4 to 15 ft | dusk & dawn | Main-lake point (16 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Break off the point (28 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 40 ft | dusk & night | Break off the point (28 ft) | Jigging rap, Jig + big minnow |
| Winter | 20 to 40 ft | dusk & dawn | Break off the point (28 ft) | Jigging spoon + minnow head, Rattle bait |
Spring puts yellow perch in skinny water — 3 to 12 ft is the zone. As the season builds they drop to 10 to 30 ft, wintering in 15 to 35 ft. Spring yellow perch concentrate at Shallow bay flat, a prime-rated weed flat around 6 ft. Warm-month bites cluster around early morning. A drop-shot micro plastics or a small spoon tipped with worm covers the summer program.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (6 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (28 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Break off the point (28 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Break off the point (28 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Spring northern pike on Isobel Lake hold shallow, usually 2 to 8 ft. By summer they slide out to 8 to 20 ft, and by winter most fish are in 5 to 15 ft. The chart's best answer is Shallow bay flat — weed flat, 6 ft, prime for spring. Prime time lands in early morning and the evening. The summer box starts with a bucktail or a weedless spoon over cabbage.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (6 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Shallow bay flat (6 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Shallow bay flat (6 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (6 ft) | Tip-ups, Large jigging spoon |
Count 6 structure marks on this chart. The deepest, Deep basin, sits near 53 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 Isobel Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Isobel Lake is about 62 ft (19 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 lake whitefish, walleye, yellow perch, northern pike on Isobel Lake.
Deep basin is the top-rated area: a deep basin in about 53 ft of water that rates prime for lake whitefish in summer. Every other rated spot, per species and season, is on the map above.
For lake whitefish, the summer bite is best in early morning. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Isobel 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.
Lyons Lake 3 mi · Greta Lake 5 mi · McQuesten Lake 8 mi · Mollison Lake 8 mi · Alfred Lake 9 mi · Springwater Lake 9 mi · Burrows Lake 9 mi · Ansig Lake 10 mi · Hutchison Lake 10 mi · Dumbbell Lake 11 mi · Hilder Lake 11 mi · Bankfield Lake 12 mi
See how Isobel Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch lakes in Ontario · best lake whitefish 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.