Lake depth chart
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117-acre lake in Thunder Bay District, Ontario. The lake tops out around 39 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. What the data behind the map says about each species, season by season:
Surprise Lake maps at 119 acres behind 3.8 miles of shoreline. With a shoreline index of 2.5, this water is all arms and coves — edge habitat well beyond its acreage. Littoral water — the productive band under ~15 ft — makes up 70% of this chart, as modeled. The basin spans about 1.3 mi end to end and 0.3 mi across at its widest. It sits in Thunder Bay District. If the bite dies, Hazelwood Lake is 2 mi to the southeast.
The spring pattern is a shallow one: lake whitefish in 12 to 39 ft. The depth story barely changes: 12 to 39 ft through summer, 12 to 39 ft in winter. Top water on the chart: Deep basin, a deep basin in the 33 ft range, prime in summer. Time it for early morning. Summer baits: a blade bait vertical or a small jigging spoon gets it done.
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 | 12 to 39 ft chart-limited; documented 15 to 45 ft | midday & dawn | Break off the point (18 ft) | Small jig + waxworm, Blade bait (small) |
| Summer | 12 to 39 ft chart-limited; documented 40 to 90 ft | dawn | Deep basin (33 ft) | Blade bait vertical, Small jigging spoon |
| Fall | 8 to 30 ft | dusk | Break off the point (18 ft) | Small spoon (gold), Jig + plastic larva |
| Winter | 12 to 39 ft chart-limited; documented 25 to 70 ft | midday & dawn | Deep basin (33 ft) | Jigging spoon + bead chain, Tungsten jig + waxie |
Spring puts walleye in skinny water — 4 to 15 ft is the zone. Warm water sends them out to 15 to 35 ft; cold water stacks them in 12 to 39 ft. Break off the point is the standout, a drop-off at roughly 18 ft, rated prime for fall walleye. Plan around the evening and early morning in the warm months. A crawler harness on bottom bouncer or a deep crankbait (trolled) 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 | 4 to 15 ft | dusk & dawn | Main-lake point (10 ft) | 1/8 oz jig + minnow, Hair jig |
| Summer | 15 to 35 ft | dusk & dawn | Break off the point (18 ft) | Crawler harness on bottom bouncer, Deep crankbait (trolled) |
| Fall | 12 to 39 ft chart-limited; documented 12 to 40 ft | dusk & night | Break off the point (18 ft) | Jigging rap, Jig + big minnow |
| Winter | 12 to 39 ft chart-limited; documented 20 to 40 ft | dusk & dawn | Deep basin (33 ft) | Jigging spoon + minnow head, Rattle bait |
Start shallow in spring: yellow perch sit in 3 to 12 ft that time of year. Warm water sends them out to 10 to 30 ft; cold water stacks them in 15 to 35 ft. Top water on the chart: Shallow bay flat, a weed flat in the 5 ft range, prime in spring. Fish it in early morning and you'll meet the bite. Throw a drop-shot micro plastics or a small spoon tipped with worm until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | midday & dawn | Shallow bay flat (5 ft) | Small jig + curly tail, Perch-pattern micro crank |
| Summer | 10 to 30 ft | dawn | Break off the point (18 ft) | Drop-shot micro plastics, Small spoon tipped with worm |
| Fall | 12 to 35 ft | midday | Deep basin (33 ft) | Jigging spoon (small), Perch rig / spreader |
| Winter | 15 to 35 ft | midday & dawn | Deep basin (33 ft) | Tungsten jig + spikes, Rattle spoon (small) |
Come spring, look for northern pike tight to the bank in 2 to 8 ft. They move out to 8 to 20 ft in summer and finish the year down in 5 to 15 ft. If you only fish one area, make it Shallow bay flat: a weed flat around 5 ft that scores prime in spring. Best bite is early morning and the evening. A bucktail or a weedless spoon over cabbage is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (5 ft) | #5 inline spinner, Spoon (red/white) |
| Summer | 8 to 20 ft | dawn & dusk | Break off the point (18 ft) | Bucktail, Weedless spoon over cabbage |
| Fall | 6 to 18 ft | midday & dawn | Break off the point (18 ft) | Big rubber (Bull Dawg style), Husky-style jerkbait |
| Winter | 5 to 15 ft | midday | Shallow bay flat (5 ft) | Tip-ups, Large jigging spoon |
Come spring, look for smallmouth bass tight to the bank in 3 to 12 ft. They move out to 10 to 30 ft in summer and finish the year down in 12 to 39 ft. If you only fish one area, make it Main-lake point: a point around 10 ft that scores prime in fall. Best bite is early morning and the evening. A drop shot (goby/minnow) or a ned rig is the honest summer answer here.
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 | 3 to 12 ft | dawn & dusk | Main-lake point (10 ft) | Ned rig, Tube jig |
| Summer | 10 to 30 ft | dawn & dusk | Break off the point (18 ft) | Drop shot (goby/minnow), Ned rig |
| Fall | 8 to 25 ft | midday & dawn | Main-lake point (10 ft) | Jerkbait, Blade bait |
| Winter | 12 to 39 ft chart-limited; documented 20 to 45 ft | midday | Break off the point (18 ft) | Blade bait, Hair jig |
Structure-wise the chart holds 6 features, led in depth by Deep basin at roughly 33 ft.
Access data: Geospatial Ontario - Fishing Access Points. Confirm conditions and fees locally before you launch.
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 Surprise Lake specifically, so confirm the current rules before you fish.
Check the official Ontario fishing regulations →
Surprise Lake is about 39 ft (12 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, smallmouth bass on Surprise Lake.
Deep basin is the top-rated area: a deep basin in about 33 ft of water that rates prime for lake whitefish in summer. The map above holds the full rated-spot list for every species and season.
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 Surprise 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.
Hazelwood Lake 2 mi · Trout Lake 2 mi · Greenpike Lake 3 mi · Warnica Lake 3 mi · Halfway Lake 4 mi · Island Lake 4 mi · Barnum Lake 5 mi · Two Island Lake 5 mi · Wartman Lake 5 mi · Golding Lake 5 mi · Mary Lake 7 mi · Hawkeye Lake 7 mi
See how Surprise Lake stacks up: best smallmouth bass lakes in Ontario · best walleye lakes in Ontario · best northern pike lakes in Ontario · best yellow perch 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.