NBM Dive Site Resource
Manhattan
Munising, Michigan, United States
A shallow, widely spread wooden-steamer site along the west side of the Grand Island east channel, with framing, iron strapping, rudder and machinery remaining.
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Original NBM Artwork
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 namaycushRegional Great Lakes evidence supports lake trout in cold Lake Superior water. Divers may see one moving above or beside the wreck; sightings vary by season and conditions.
Knepp Timothy, U.S. Fish and Wildlife ServiceOpen Aquatic Life Profile →
Lake Whitefish
Coregonus clupeaformisLake whitefish occupy cold Great Lakes habitat and may pass near wreck structure or the adjacent bottom. Treat this as a possible, condition-dependent encounter.
Seb951Open Aquatic Life Profile →
Burbot
Lota lotaNOAA reports burbot at deeper Great Lakes wrecks and in cold bottom habitat. A sighting near timbers, machinery, or the lakebed is possible but never guaranteed.
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 | 14.3°F / -9.8°C | 36.7°F / 2.6°C | No reliable record | — |
| Feb | 15.8°F / -9.0°C | 34.9°F / 1.6°C | No reliable record | — |
| Mar | 25.0°F / -3.9°C | 36.6°F / 2.6°C | No reliable record | — |
| Apr | 36.8°F / 2.7°C | 36.8°F / 2.7°C | No reliable record | — |
| May | 50.6°F / 10.3°C | 36.4°F / 2.4°C | No reliable record | — |
| Jun | 60.7°F / 15.9°C | 38.2°F / 3.4°C | No reliable record | — |
| Jul | 65.3°F / 18.5°C | 44.6°F / 7.0°C | No reliable record | — |
| Aug | 63.6°F / 17.6°C | 55.7°F / 13.2°C | No reliable record | — |
| Sep | 56.3°F / 13.5°C | 55.4°F / 13.0°C | No reliable record | — |
| Oct | 43.5°F / 6.4°C | 49.2°F / 9.6°C | No reliable record | — |
| Nov | 30.8°F / -0.7°C | 43.4°F / 6.3°C | No reliable record | — |
| Dec | 20.2°F / -6.6°C | 39.9°F / 4.4°C | No reliable record | — |
NOAA NCEI 1991–2020 U.S. Climate Normals — Marquette, MI
1991–2020 climate normalsReview source ↗NOAA NCEI Coastal Water Temperature Guide — East Superior
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
Massive hull timbers, distinctive iron strapping and a large rudder across several depth zones.
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
- Wooden bulk-freight steamer
- Year built
- 1887
- Year sunk
- 1903
- Vessel length
- 252 ft
- Cause of loss
- Steering-chain failure, grounding and fire
- Wreck orientation
- Widely scattered along the channel
- Present condition
- Hull framing, rudder, deck fittings and machinery remain
- Penetration guidance
- No intact vessel penetration; monitor boat traffic and channel navigation
- Protection or memorial status
- Alger Underwater Preserve
History and significance
Manhattan burned to the waterline after striking a reef while leaving shelter behind Grand Island. Later salvage and channel-clearance work dispersed the remains.
Plan the trip
Dive boats that visit this wreck
Shipwreck Tours lists this among the most popular wrecks it scuba dives and may assign either Hannah Marie or Wreck Express based on the trip.
Open boat profile →Munising, MichiganWreck Express — Munising Shipwreck Dive CharterShipwreck Tours, Inc.Shipwreck Tours lists this among the most popular wrecks it scuba dives and may assign either Hannah Marie or Wreck Express based on the trip.
Open boat profile →Regional context
Located within
Before you arrive
Access notes
Confirm the selected wreck, departure, current conditions, mooring status and diver requirements directly with the operator. 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, changing visibility, boat traffic, entanglement and fragile or unstable wreck structure. Depth-specific decompression and overhead hazards may apply.
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.