NBM Dive Site Resource
Colonel A. B. Williams
Port Sanilac, Michigan, United States
A mostly intact 110-foot schooner sitting upright in about 84 feet of water, with a collapsed stern and substantial deck equipment remaining.
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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.
Lake Trout
Salvelinus namaycushColonel A. B. Williams rests upright in about 84 feet of Lake Huron water. Lake trout use a wide depth range, and a passing fish is plausible when the wreck lies in cold water.
Knepp Timothy, U.S. Fish and Wildlife ServiceOpen Aquatic Life Profile →
Lake Whitefish
Coregonus clupeaformisLake whitefish are an important documented Lake Huron fish that favor cool bottom habitat. Divers may see one passing the wreck or adjacent lakebed.
Seb951Open Aquatic Life Profile →
Burbot
Lota lotaNOAA notes that burbot often appear at deeper Lake Huron shipwrecks. Look close to shaded lower structure and the bottom without entering confined areas.
USFWS Mountain-PrairieOpen 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 | 25.8°F / -3.4°C | 34.1°F / 1.2°C | No reliable record | — |
| Feb | 28.0°F / -2.2°C | 33.8°F / 1.0°C | No reliable record | — |
| Mar | 37.2°F / 2.9°C | 35.9°F / 2.2°C | No reliable record | — |
| Apr | 48.9°F / 9.4°C | 37.0°F / 2.8°C | No reliable record | — |
| May | 60.3°F / 15.7°C | 40.0°F / 4.4°C | No reliable record | — |
| Jun | 69.9°F / 21.1°C | 51.1°F / 10.6°C | No reliable record | — |
| Jul | 74.1°F / 23.4°C | 63.9°F / 17.7°C | No reliable record | — |
| Aug | 72.3°F / 22.4°C | 68.6°F / 20.3°C | No reliable record | — |
| Sep | 64.9°F / 18.3°C | 64.8°F / 18.2°C | No reliable record | — |
| Oct | 53.0°F / 11.7°C | 56.4°F / 13.6°C | No reliable record | — |
| Nov | 41.2°F / 5.1°C | 48.2°F / 9.0°C | No reliable record | — |
| Dec | 31.3°F / -0.4°C | 44.0°F / 6.7°C | No reliable record | — |
NOAA NCEI 1991–2020 U.S. Climate Normals — Detroit Metro, MI
1991–2020 climate normalsReview source ↗NOAA NCEI Coastal Water Temperature Guide — South Huron
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
Hatches, stove, bilge pump, winches and a large windlass.
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.
Plan the trip
Dive boats that visit this wreck
Regional context
Located within
Before you arrive
Access notes
Adventure I uses Port Sanilac for the Sanilac Shores Underwater Preserve. Published coordinates support regional discovery and are not a substitute for current navigation, active mooring information, operator guidance, permits, weather, or a dive plan.
Plan within your training
Conditions and hazards
Cold water, fragile wood structure and changing Lake Huron conditions.
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.