NBM Dive Site Resource
Milwaukee Caisson
Milwaukee, Wisconsin, United States
TECHNICAL DIVE REQUIRED FOR THE DEEPER SECTIONS — Submerged industrial caisson structure off Milwaukee spanning advanced recreational to technical depths.
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Historic Picture Placeholder
Aquatic life at this dive site
What divers may encounter
Three reviewed connections are featured here. Sightings vary by season, conditions, and chance, so they are never guaranteed.
Lake Trout
Salvelinus namaycushThe Milwaukee Caisson rises from a Lake Michigan bottom near 150 feet. NOAA identifies lake trout in Wisconsin Shipwreck Coast waters and notes that submerged structures provide foraging habitat for predatory fish. Sightings remain season- and condition-dependent.
Knepp Timothy, U.S. Fish and Wildlife ServiceOpen Aquatic Life Profile →
Burbot
Lota lotaNOAA reports that burbot often appear at deeper Great Lakes wrecks and structures. Divers may encounter one near the caisson or bottom, but sightings are never assured.
USFWS Mountain-PrairieOpen Aquatic Life Profile →
Round Goby
Neogobius melanostomusNOAA identifies round goby among Lake Michigan bottom-habitat fishes. Look along the caisson base, internal bracing, and adjoining lakebed while accounting for depth and visibility.
Peter van der SluijsOpen Aquatic Life Profile →
Site media
Photographs
Three views rotate from the published gallery on each visit.
Contributor media
Dive videos
Three featured video positions are reserved on every profile.Published reference location
Location map
The marker shows the public coordinates associated with this profile. Confirm current access, moorings, and departure details before the dive.Map data © OpenStreetMap contributors
Recent field observations
Diver-reported temperatures
Automatically checked observations from dives during the past 14 days. Three reports are visible at a time; scroll for more.A report that passes the automatic checks will appear here with the dive date, diver’s display name, and temperatures at each depth.
Reports are automatically checked for plausible dates, depths, and temperatures. They are observations, not forecasts; confirm conditions before diving.
Seasonal planning reference
Typical monthly conditions
Long-term averages, not a forecast. Actual air and water conditions can change quickly and may vary across the site.Moderate-confidence match — Matched by documented Great Lakes port/area. Air and surface-water values are regional planning averages. No bottom-water line is published because a comparable depth-specific record has not yet been verified.
| Month | Average air | Surface water | Bottom water | Bottom measurement depth |
|---|---|---|---|---|
| Jan | 24.0°F / -4.4°C | 35.2°F / 1.8°C | No reliable record | — |
| Feb | 27.1°F / -2.7°C | 36.6°F / 2.6°C | No reliable record | — |
| Mar | 36.4°F / 2.4°C | 37.8°F / 3.2°C | No reliable record | — |
| Apr | 46.3°F / 7.9°C | 38.3°F / 3.5°C | No reliable record | — |
| May | 57.1°F / 13.9°C | 42.5°F / 5.8°C | No reliable record | — |
| Jun | 67.6°F / 19.8°C | 53.7°F / 12.1°C | No reliable record | — |
| Jul | 73.3°F / 22.9°C | 68.2°F / 20.1°C | No reliable record | — |
| Aug | 72.3°F / 22.4°C | 72.2°F / 22.3°C | No reliable record | — |
| Sep | 65.0°F / 18.3°C | 68.4°F / 20.2°C | No reliable record | — |
| Oct | 53.0°F / 11.7°C | 58.5°F / 14.7°C | No reliable record | — |
| Nov | 40.4°F / 4.7°C | 49.0°F / 9.4°C | No reliable record | — |
| Dec | 29.5°F / -1.4°C | 43.7°F / 6.5°C | No reliable record | — |
Wisconsin State Climatology Office — Milwaukee Climate Data
1991–2020 climate normalsReview source ↗NOAA NCEI Coastal Water Temperature Guide — Station 45007
Historical monthly station averagesReview source ↗Bottom temperature is never inferred from surface temperature. A blank month means no reliable depth-specific average is available. Data reviewed 2026-08-26.
Why divers know this place
Highlights
Upright steel-reinforced concrete industrial structure approximately 50 feet tall and 50 feet in diameter.
Shipwreck-only module
The wreck
This section appears only on shipwreck records and brings the vessel, its loss, present condition, access, and responsible wreck-diving considerations into one place.
- Vessel type
- Submerged industrial caisson
- Vessel length
- Approximately 50 ft tall and 50 ft in diameter
- Cause of loss
- Original placement or loss circumstances remain undocumented
- Wreck orientation
- Vertical and upright
- Present condition
- Open cylindrical structure with internal steel bracing and a low wall opening.
- Penetration guidance
- Internal bracing and fine sediment create overhead and entanglement hazards. Entry requires appropriate training and equipment.
History and significance
This steel-reinforced concrete structure is an industrial dive site rather than a vessel wreck. Its original function, installation date and project have not been established. The visible framework suggests a caisson that was never completely filled; whether it was placed intentionally or sank during transport remains uncertain.
Plan the trip
Dive boats that visit this wreck
Before you arrive
Access notes
Approximately 7.4 miles northeast of Milwaukee; upright artificial structure about 50 feet tall; confirm current charter and mooring conditions.
Plan within your training
Conditions and hazards
Cold water, depth, decompression risk, overhead areas, entanglement and variable visibility. The deepest sections may create decompression obligations; cold water, limited visibility, entanglement and overhead wreckage require site-specific planning.
Independent resource notice
This record is a starting point for independent verification. Access, closures, moorings, weather, currents, depth, visibility, operator availability, and site conditions can change without notice. Confirm current information with the responsible operator, property owner, managing authority, or another qualified local source before planning or attempting a dive.