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Map of Hennepin Wreck
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ExpertBoat entry

Hennepin Wreck

Michigan, United States
Extreme depth (230 ft)70 m depthBoat entry

Boat dive — see Entry & access.

Hennepin Wreck at a glance

Hennepin Wreck is a expert boat dive site in Michigan, United States with depths of up to 70 m (230 ft). Typically most favorable Jul · from 3 years of archive data. Divers commonly see Burbot and Quagga mussel. Check the latest conditions and entry details before you go.

Wind model · graded 5h ago
—

Tap a factor for its source and model point

Site hazards: Extreme depth (230 ft) · Severe cold and darkness at depth · Long offshore boat ride in open Lake Michigan

All 4 hazards ↓

Dive windows this week

Best: Fri
Sun7:00–22:00
Mon8:00–22:00
Tue7:00–16:00
Wed7:00–22:00
Thu7:00–22:00
Fri7:00–22:00
Sat7:00–22:00

Favorable windowModerate window— no window

First light 6:01 · Sunrise 6:33 · Sunset 21:13

Source: Open-Meteo wind · graded 5h ago

Forecast only — always assess conditions on site.

Forecast · NOAA tide model

Tide & slack timing

Loading tide predictions

Recent diver reports

Dated firsthand observations from divers — not current conditions.

No diver reports for this site yet. — one dated observation helps every diver after you.

What Divers Say

Best time: Mid-summer (June-September) on flat-calm days only, given the offshore distance.

Based on community reviews and site data. Conditions vary — always verify before diving.

Best months, historically

What conditions have historically been typical at this site, month by month — not a forecast.

  1. Jan12% 20 kn
  2. Feb14% 20 kn
  3. Mar11% 20 kn
  4. Apr22% 18 kn
  5. May37% 16 kn
  6. Jun36% 15 kn
  7. Jul56% 14 kn
  8. Aug44% 15 kn
  9. Sep51% 14 kn
  10. Oct17% 19 kn
  11. Nov9% 21 kn
  12. Dec10% 21 kn

July hastypically had the largest share of favorable days here. Conditions vary year to year — this is historical context, not a forecast.

Based on 3 years of archive data. Bar height shows the share of days each month whose conditions have historically scored favorably.

Marine life seen at this site

Species noted at this site — not a promise of what you’ll encounter.

Species seen here

  • BurbotOccasionally seen
  • Quagga musselCommonly seen

Fills & rentals nearby

No dive shops mapped within 25 km. Know one? Add it to the map.

Site details

The Hennepin, built 1888 and converted in 1902 into the world's first self-unloading bulk carrier, foundered on August 18, 1927 about 15-20 miles off South Haven; her entire conveyor and A-frame unloading system is still in place. Located by Michigan Shipwreck Research Associates in 2006, she sits upright in about 230 ft of Lake Michigan within the Southwest Michigan Underwater Preserve. This is a serious trimix technical dive — cold, dark, and far offshore — but historically one of the most important wrecks in the Great Lakes.

boatwreck

Extreme depth (230 ft) — trimix decompression dive only

Severe cold and darkness at depth

Long offshore boat ride in open Lake Michigan

Entanglement in the self-unloading conveyor structure, A-frame and rigging

Reviews

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