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1,414-acre Casco Passage fishing map with NOAA BlueTopo survey contours (100% measured, 100% assessed), charted rock and wreck structure, regional fish-survey occurrence, sourced forage timing and verified public access. The water tops out around 90 ft. The depth chart is built from real agency bathymetry referenced to NAVD88; directly measured coverage remains distinguished from source interpolation. The channels, holes and drop-offs come from the source data, not a distance-from-shore model. What the data behind the map says about each species, season by season:
On the chart, Casco Passage draws 1,412 acres inside 10.3 miles of shoreline — 14 islands included. The shoreline is moderately structured (index 2) — enough points and pockets to pattern. 11% of the surface is littoral (under ~15 ft) — cover, weeds and forage water. Figure 2.5 mi of water from one end to the other, 1.5 mi at the beam. For a second option, Mackerel Cove lies 1 mi southeast.
Come spring, look for striped bass tight to the bank in 5 to 20 ft. Expect a summer slide to 25 to 60 ft, then a winter hold in 20 to 50 ft. Start at Surveyed channel edge. It's a drop-off holding about 25 ft of water and rates prime come summer. Prime time lands in early morning and the evening. A flutter spoon (deep) or an umbrella rig (trolled) is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 20 ft | dawn & dusk | Surveyed channel edge (25 ft) | Bucktail jig + trailer, Walking topwater (dawn) |
| Summer | 25 to 60 ft | dawn & dusk | Surveyed channel edge (25 ft) | Flutter spoon (deep), Umbrella rig (trolled) |
| Fall | 10 to 35 ft | dawn & dusk | Surveyed channel edge (25 ft) | Topwater walker, Jerkbait |
| Winter | 20 to 50 ft | midday | Surveyed channel edge (25 ft) | Alabama rig (slow), Flutter spoon |
The spring pattern is a shallow one: bluefish in 3 to 20 ft. Midsummer fish sit out in 5 to 30 ft before dropping to 15 to 40 ft for winter. The spot to know is Surveyed channel edge, a drop-off in about 25 ft of water that rates prime for bluefish in summer. Plan around early morning and the evening in the warm months. Summer baits: a popper (early/late) or a metal jigs in the rips gets it done.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 20 ft | dawn & dusk | open water | Metal (Hopkins/Kastmaster), Pencil popper |
| Summer | 5 to 30 ft | dawn & dusk | Surveyed channel edge (25 ft) | Popper (early/late), Metal jigs in the rips |
| Fall | 3 to 25 ft | dawn & midday | Surveyed channel edge (25 ft) | Pencil popper, Big metal |
| Winter | 15 to 40 ft | midday | Surveyed channel edge (25 ft) | Metal jig worked slow (southern waters) |
Come spring, look for atlantic mackerel tight to the bank in 5 to 45 ft. They move out to 15 to 80 ft in summer and finish the year down in 23 to 90 ft. If you only fish one area, make it Surveyed channel edge: a drop-off around 25 ft that scores prime in summer. Best bite is early morning and the evening. A feather rig or a small vertical jig is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 45 ft | dawn & dusk | Surveyed channel edge (25 ft) | Mackerel feather rig, Small silver jig |
| Summer | 15 to 80 ft | dawn & dusk | Surveyed channel edge (25 ft) | Feather rig, Small vertical jig |
| Fall | 10 to 65 ft | dawn & dusk | Surveyed channel edge (25 ft) | Compact silver jig, Sparse feather rig |
| Winter | 23 to 90 ft | midday | Surveyed channel edge (25 ft) | Small deep jig |
Early season atlantic cod use the shallows, holding in 18 to 90 ft. Even in summer they hold at 23 to 90 ft; winter keeps them in 20 to 90 ft. The chart's best answer is NOAA charted underwater rock — rock pile, 27 ft, prime for spring. Best bite is early morning. Tie on a heavy metal jig or a large soft-plastic jig and you're in the game.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 18 to 90 ft | dawn | NOAA charted underwater rock (27 ft) | Diamond jig, Heavy bucktail |
| Summer | 23 to 90 ft | dawn | NOAA charted underwater rock (27 ft) | Heavy metal jig, Large soft-plastic jig |
| Fall | 16 to 90 ft | dawn | NOAA charted underwater rock (16 ft) | Diamond jig, Bucktail with teaser |
| Winter | 20 to 90 ft | midday | NOAA charted underwater rock (27 ft) | Heavy vertical jig |
Start shallow in spring: atlantic herring sit in 5 to 25 ft that time of year. Warm water sends them out to 15 to 50 ft; cold water stacks them in 20 to 60 ft. Top water on the chart: Surveyed channel edge, a drop-off in the 25 ft range, prime in summer. Fish it in early morning and the evening and you'll meet the bite. Throw a herring feather rig or a small silver jig until the fish tell you otherwise.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 25 ft | dawn & dusk | NOAA charted underwater rock (9 ft) | Small herring feather rig, Micro jig rig |
| Summer | 15 to 50 ft | dawn & dusk | Surveyed channel edge (25 ft) | Herring feather rig, Small silver jig |
| Fall | 10 to 40 ft | dawn & dusk | Surveyed channel edge (25 ft) | Small feather rig, Compact silver spoon |
| Winter | 20 to 60 ft | midday | Surveyed channel edge (25 ft) | Small silver jig, Sparse feather rig |
Structure-wise the chart holds 28 features, led in depth by Surveyed channel edge at roughly 52 ft.
Access data: Maine GeoLibrary — Boat Launches (Maine IF&W / DACF). Confirm conditions and fees locally before you launch.
Season dates, license requirements, and size and bag limits for Maine waters are set by the Maine DMR (saltwater recreational fishing) — and special regulations can apply to Casco Passage specifically, so confirm the current rules before you fish.
Check the official Maine fishing regulations →
Casco Passage is about 90 ft (27 m) deep at its deepest point. The depth chart is built from real agency bathymetry referenced to NAVD88; directly measured coverage remains distinguished from source interpolation. The contours reflect measured and quality-assessed source depths.
Anglers target striped bass, bluefish, atlantic mackerel, atlantic cod, atlantic herring on Casco Passage.
NOAA charted underwater rock is the top-rated area: a rock pile in about 27 ft of water that rates prime for atlantic cod in spring. Every other rated spot, per species and season, is on the map above.
For striped bass, 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 Casco Passage is regulated by the Maine DMR (saltwater recreational fishing). Check the official Maine regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Mackerel Cove 1 mi · Blue Hill Bay 3 mi · Goose Pond 3 mi · Eastern Passage 3 mi · Jericho Bay 4 mi · Toothacher Bay 4 mi · Bass Harbor 5 mi · Naskeag Harbor 6 mi · Bass Harbor Bar 6 mi · Boxam Cove 7 mi · Southwest Harbor 9 mi · Southeast Harbor 9 mi
See how Casco Passage stacks up: best striped bass lakes in Maine · best bluefish lakes in Maine · best atlantic herring lakes in Maine · best atlantic mackerel lakes in Maine
Browse all Maine fishing maps or see every water on DepthScout. Bathymetry credit: NOAA BlueTopo (NAVD88; 100% measured, 0% source-interpolated). 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.