NBM Dive Site Resource
Alaska
Wisconsin Shipwreck Coast, Wisconsin, United States
Officially inventoried shipwreck in Wisconsin Shipwreck Coast National Marine Sanctuary. Verify current conditions, access, permits, and mooring status before diving.
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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.
Zebra Mussel
Dreissena polymorphaNOAA reports that invasive zebra and quagga mussels first colonized shallow, well-lit wrecks and are commonly attached to sanctuary shipwreck sites.
no rights reservedOpen Aquatic Life Profile →
Quagga Mussel
Dreissena rostriformis bugensisNOAA reports zebra and quagga mussels on most Lake Michigan wrecks. Alaska is a five-foot wreck that is periodically exposed from shifting sand.
Motte123Open Aquatic Life Profile →
Round Goby
Neogobius melanostomusNOAA associates round gobies with the sanctuary’s rocky bottom habitat. At Alaska, look around exposed hull structure; shifting sand can greatly change available habitat.
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.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
A source-checked Great Lakes dive location within Wisconsin Shipwreck Coast National Marine Sanctuary.
Regional context
Located within
Before you arrive
Access notes
The official inventory establishes this location within the protected area; access method and seasonal mooring availability can change.
Plan within your training
Conditions and hazards
Cold freshwater, limited visibility, changing weather and currents, boat traffic, entanglement, and overhead hazards around wreckage.
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.