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Map of SS Onoko Wreck
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ExpertBoat entry

SS Onoko Wreck

Minnesota, United States
Extreme depth (~220 ft)55–67 m (180–220 ft) depthBoat entry

Boat dive — see Entry & access.

SS Onoko Wreck at a glance

SS Onoko Wreck is an expert boat dive site in Minnesota, United States with depths of 55–67 m (180–220 ft). Typically most favorable Jul · from 3 years of archive data. Divers commonly see Burbot. Check the latest conditions and entry details before you go.

Next window today· 8:00–19:00 · favorable & moderate · sunset 18:00

Wind forecast for this hour · 4:00 · run 3 h ago
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Tap a factor for its source and model point

Site hazards: Extreme depth (~220 ft) · Very cold water (~2-4 C) at depth · Inverted, broken hull

All 6 hazards ↓

Dive windows this week

Lightest wind: Sun
Mon8:00–17:00 favorable, 17:00–19:00 moderate

13 kn wind (13 kn wind)

Tue9:00–16:00 moderate, 16:00–18:00 favorable

16 kn wind (16 kn wind)

Wed8:00–12:00 favorable, 12:00–15:00 moderate, 15:00–18:00 favorable

6 kn wind (6 kn wind)

Thu8:00–9:00 favorable, 9:00–10:00 moderate, 10:00–18:00 favorable

8 kn wind (8 kn wind)

Fri8:00–18:00 favorable

5 kn wind (5 kn wind)

Sat8:00–18:00 favorable

6 kn wind (6 kn wind)

Sun8:00–18:00 favorable

4 kn wind (4 kn wind)

Favorable windowModerate window— no window

Every forecast dive window each day, site-local time, from wind forecasts. Numbers under each bar are daylight averages.

First light 7:09 · Sunrise 7:41 · Sunset 18:00 · some windows run past sunset

Source: Open-Meteo wind · updated 26 Oct, 00:28 GMT-5

Forecast only — always assess conditions on site.

Compare this weekend’s windows near SS Onoko Wreck

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.

Dived here today — did the forecast match?

What Divers Say

Best time: Mid-summer to early fall on flat-calm forecasts.

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. January, 87% of days have historically been favorable, wind has typically been 10 knots
  2. February, 86% of days have historically been favorable, wind has typically been 11 knots
  3. March, 84% of days have historically been favorable, wind has typically been 11 knots
  4. April, 80% of days have historically been favorable, wind has typically been 11 knots
  5. May, 88% of days have historically been favorable, wind has typically been 10 knots
  6. June, 92% of days have historically been favorable, wind has typically been 9 knots
  7. July, 99% of days have historically been favorable, wind has typically been 8 knots, historically most favorable
  8. August, 96% of days have historically been favorable, wind has typically been 9 knots
  9. September, 93% of days have historically been favorable, wind has typically been 9 knots
  10. October, 96% of days have historically been favorable, wind has typically been 10 knots
  11. November, 82% of days have historically been favorable, wind has typically been 11 knots
  12. December, 78% of days have historically been favorable, wind has typically been 11 knots

July has typically 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

Rough labels: “Commonly seen” usually means two or more recorded sightings near this site in public dive logs (GBIF), “Occasionally seen” one; “Seasonal” and “Rarely seen” come from dive-guide research. Not a measured rate.

Fills & rentals nearby

No dive shops mapped within 25 km (16 mi). Know one? Add it to the map.

Data updated June 2026

Site details

The Onoko, launched in 1882, was the first iron-hulled bulk freighter on the Great Lakes and a direct ancestor of the modern laker. She sprang a leak and sank in 35 minutes on September 14, 1915, about 13.5 nautical miles east of Duluth, and was found in 1988 lying upside down and broken nearly in half in roughly 220 feet of water. It is a serious trimix-level technical dive: dark, silty, very cold and far offshore, visited only by experienced technical teams.

boatwreck

Extreme depth (~220 ft) — trimix/CCR technical dive only

Very cold water (~2-4 C) at depth

Low visibility and heavy silt over the mud bottom

Inverted, broken hull — disorientation and entanglement risk

Open-lake location 13.5 nm east of Duluth, weather-dependent

Mandatory staged decompression

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