Lake depth chart
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Reopens January 1 · FMZ 3 or 8 zone-wide season. Lake-specific exceptions and sanctuaries can differ — check the official summary before you go.
Recent public catches load as you reach this section.
16-acre lake in Cochrane District, Ontario. The lake tops out around 25 ft. The depth chart comes from Ontario Ministry of Natural Resources and Forestry 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.
The outline encloses 15 acres, worked by 0.7 miles of shoreline. The basin is a simple one (shoreline index 1.2) — close to a bowl, so the structure on the chart matters more than the bank. Roughly 91% of the water is 15 ft or less, the band where the food chain lives. End to end it runs roughly 0.3 mi. Cochrane District claims this one. Marten Lake sits 1 mi southeast — the closest neighbouring chart.
Early season brook trout use the shallows, holding in 2 to 15 ft. Summer is an 8 to 25 ft game here, winter a 3 to 20 ft one. The chart's best answer is Deep basin — deep basin, 20 ft, prime for summer. Best bite is early morning and the evening. Tie on a small spoon fished deep or a trolled lake-clear wobbler + worm and you're in the game.
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 | 2 to 15 ft | dawn & dusk | Main-lake point (1 ft) | Small inline spinner (gold), Tiny spoon |
| Summer | 8 to 25 ft chart-limited; documented 10 to 30 ft | dawn & dusk | Deep basin (20 ft) | Small spoon fished deep, Trolled lake-clear wobbler + worm |
| Fall | 2 to 15 ft | midday & dawn | Main-lake point (1 ft) | Small spoon (orange), Spinner |
| Winter | 3 to 20 ft | dawn | Deep basin (20 ft) | Small jigging spoon, Tungsten jig + plastic |
In spring, walleye run shallow here, mostly 4 to 15 ft. Summer pushes them deeper, 8 to 25 ft, and winter fish settle into 8 to 25 ft. Break off the point is the standout, a drop-off at roughly 10 ft, rated prime for fall walleye. Time it for the evening and early morning. You won't need more than a crawler harness on bottom bouncer or a deep crankbait (trolled) most summer days.
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 | 4 to 15 ft | dusk & dawn | Break off the point (10 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 8 to 25 ft chart-limited; documented 15 to 35 ft | dusk & dawn | Break off the point (10 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 8 to 25 ft chart-limited; documented 12 to 40 ft | dusk & night | Break off the point (10 ft) | Jigging rap, Jig + big minnow |
| Winter | 8 to 25 ft chart-limited; documented 20 to 40 ft | dusk & dawn | Deep basin (20 ft) | Jigging spoon + minnow head, Rattle bait |
When the water first warms, northern pike slide up into 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. If you only fish one area, make it Break off the point: a drop-off around 10 ft that scores prime in fall. In summer the feeding windows fall in early morning and the evening. Keep a bucktail or a weedless spoon over cabbage rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | open water | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (10 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (10 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Break off the point (10 ft) | Tip-ups, Large jigging spoon |
3 pieces of structure are mapped here — Deep basin, around 20 ft, is the deepest of them.
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 Rat Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Rat Lake is about 25 ft (8 m) deep at its deepest point. The depth chart comes from Ontario Ministry of Natural Resources and Forestry bathymetric survey data, so the contours are survey-derived rather than computer-modeled.
Anglers target brook trout, walleye, northern pike on Rat Lake.
Break off the point is the top-rated area: a drop-off in about 10 ft of water that rates prime for walleye in fall. The interactive chart above rates every 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 Rat 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.
Marten Lake 1 mi · Little Esker Lake 3 mi · Campbell Lake 3 mi · Bea Lake 3 mi · Mary Lake 4 mi · Thrasher Lake 4 mi · Mall Lake 4 mi · Lulu Lake 4 mi · Gaf Lake 4 mi · Pall Lake 4 mi · Verna Lake 4 mi · Stever Lake 4 mi
See how Rat Lake stacks up: best walleye lakes in Ontario · best northern pike lakes in Ontario · best brook trout lakes in Ontario
More water nearby: Cochrane District fishing maps (673 charts). Browse all Ontario fishing maps. See every water on DepthScout. Depth data: Ontario Ministry of Natural Resources and Forestry, Lake survey data (Open Government Licence – Ontario). 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.