Lake Michigan Shipwreck Diving FAQ
Great Lakes Diving
The cold freshwater of the Great Lakes preserves shipwrecks exceptionally well, especially historic wooden vessels that can remain intact even after more than a century underwater. Unlike in the ocean, wrecks in freshwater are not rapidly broken down by saltwater corrosion, marine organisms, or powerful ocean storms.
The consistently cold temperatures act almost like a giant underwater refrigerator, slowing the natural decay process. Divers can explore historic schooners, steamers, and freighters that still display structural details such as masts, railings, cargo holds, and deck equipment. In many cases, these wrecks feel like underwater time capsules, offering a unique glimpse into Great Lakes maritime history.
The Great Lakes are a group of five large freshwater lakes located along the border between the United States and Canada. They include Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, and together form the largest freshwater lake system in the world by surface area. The other four lakes form part of the international border between the U.S. and Canada.
Shipwreck Explorers charters primarily dive shipwrecks in Lake Michigan, based out of Milwaukee and operating from ports along the Wisconsin shoreline.
General Questions
Yes. All divers must hold a recognized scuba certification and dive within the limits of their training and experience. Divers are responsible for planning and conducting their own dives.
Dives are generally not guided. A surface briefing is provided about the wreck, mooring location, and conditions, and divers plan and conduct their own dives.
If a dive guide is requested, one can usually be arranged in advance. Since the boat is limited to six divers, the guide’s space on the boat would need to be covered by the requesting diver or group.
Trips are limited to six divers, which allows plenty of space for gear and a relaxed atmosphere on board. The small group size also makes it easier to coordinate dive plans and manage equipment between dives.
Some expedition-style trips may be limited to five divers due to the additional equipment typically involved.
Booking & Reservations
You can reserve a spot directly through the Dive Schedule page on the website or contact Shipwreck Explorers to arrange off-schedule or group trips.
Yes. Private charters are available and are a great option for dive shops, dive clubs, or groups of friends.
Weekend trips during the summer season can fill quickly, so booking ahead is recommended. However, it is often possible to join a day trip on shorter notice as space allows.
Multi-day expedition trips typically require more advance planning, especially for divers traveling from outside the region.
Lake Michigan conditions can change quickly. If weather or waves make diving unsafe, the trip may be rescheduled or canceled.
Captains monitor weather conditions in the days leading up to a trip and will sometimes notify divers of cancellations a day or two in advance. When conditions are borderline, the final decision may be made the morning of the trip.
Diving Logistics
Most trips depart from Milwaukee, Wisconsin, though some charters may operate from other Wisconsin ports depending on the destination wreck, including Kenosha, Port Washington, Sheboygan, and Manitowoc/Two Rivers.
Wisconsin shipwrecks range from about 50 ft to 320 ft (15–98 m) in depth, offering opportunities for recreational, advanced recreational, entry-level technical, and advanced technical divers.
Divers are expected to bring their own dive equipment. If a diver needs a full set of rental gear, it should be arranged through a local dive shop.
For traveling divers, we can usually help arrange tanks, weights, and rebreather sorb with advance notice. Local divers may also rent tanks if needed.
Boat & Dive Operations
Most recreational trips and technical trips to depths of about 200 ft plan for two dives, usually on two different wrecks but sometimes on the same wreck.
Divers booking the entire boat have more flexibility. Some groups choose to do only one technical dive or a combination of a technical and a recreational dive.
Advanced technical divers planning dives deeper than about 220 ft typically plan one dive per day.
Trip length depends on the destination wreck and departure port and accounts for boat loading and unloading, travel time to the shipwrecks, and either two dives with a surface interval or a single dive.
- Two-dive recreational trip lasts about ½ day (4–5 hours)
- Two-dive technical trip lasts about ⅔ of a day (6–7 hours)
- A single evening recreational dive trip lasts about 3 hours
- Expedition-style dive trip may last the entire day
Bottled water is provided so divers can stay hydrated during the day. Food is not included, but divers are welcome to bring their own meals or snacks.
Yes. The boat regularly supports both recreational and technical divers, including those diving doubles, sidemount, or rebreathers, along with stage or bailout bottles. Deck benches have storage space underneath for stage or bailout bottles.
For trips involving a large amount of equipment—such as extra tanks, scooters, or large camera systems—it may be recommended to limit the group to five divers to ensure adequate space.
Yes. Molly V is equipped with a sturdy dive ladder designed specifically for divers wearing heavy gear. The ladder extends well below the waterline and has comfortable step spacing to make climbing out easier. As we like to say during the dive briefing, “Molly V has the best dive ladder in the Great Lakes.”
Yes. Molly V has two equipment lines at the stern that extend about 22 ft below the surface. Each line has attachment rings where divers can clip stage or bailout bottles.
Some divers prefer to clip bottles to the line and pick them up in the water, rather than gearing up with the extra weight on the boat deck.
When exiting the water, we recommend clipping stage bottles to the line or handing them up at the swim platform before climbing the ladder to reduce weight.
Yes. On many technical dives, Molly V deploys a Carolina rig that connects the stern area to the main mooring line at about 20 ft depth. This helps divers get below the surface chop quickly, provides support in surface current, creates additional space during decompression, and keeps the emergency oxygen easy to locate near the line.
Because of the configuration of some recreational moorings, this system is used primarily on technical dives.
Experience & Conditions
Yes. Water temperatures are cold year-round, and a drysuit is recommended for most dives. Bottom temperatures remain fairly consistent throughout the year at about 40°F (4.4°C), sometimes slightly warmer on shallower recreational dives and colder on deeper technical dives.
By mid-June, surface water temperatures begin to warm, making recreational dives and decompression stops on technical dives more comfortable. In the middle of summer, surface temperatures can reach 75°F (24°C), with thermoclines sometimes extending down to about 100 ft.
Sometimes. Lake Michigan diving is cold year-round, and a drysuit is recommended for most dives. Bottom temperatures remain fairly consistent at about 40°F (4.4°C) throughout the year.
By mid-June, surface water temperatures begin to warm, and some divers choose to dive in a thick 7 mm wetsuit or semi-drysuit, particularly on shallower recreational dives. Surface temperatures can reach 75°F (24°C) in mid-summer, with thermoclines sometimes extending down to about 100 ft.
For deeper dives or technical dives, however, a drysuit is strongly recommended due to the consistently cold bottom temperatures.
Visibility varies depending on weather and conditions but can range from moderate to excellent, especially on deeper wrecks. Lake Michigan waters have become noticeably clearer since the arrival of invasive zebra and quagga mussels, which filter the water.
Years ago, visibility was often only around 10 ft, but today it commonly ranges from 20 ft on a poor day to over 100 ft on exceptional days.
Some shipwrecks closer to the Milwaukee River may experience reduced visibility later in the summer or after heavy rain and strong storms, while wrecks farther offshore often enjoy excellent visibility most of the time.
Shipwreck Preservation
No. Historic shipwrecks in Wisconsin waters are protected archaeological sites. State law prohibits removing artifacts, damaging wrecks, or disturbing the site without a permit from the Wisconsin Historical Society.
Many shipwrecks between Port Washington and Two Rivers are also protected by the Wisconsin Shipwreck Coast National Marine Sanctuary, which provides additional federal protections.
Responsible divers follow a simple rule: take only pictures, leave only bubbles, and leave artifacts in place for others to enjoy.
Mooring lines allow divers to descend directly onto wrecks without dropping anchors, helping protect fragile historic sites.
Within the Wisconsin Shipwreck Coast National Marine Sanctuary, permanent moorings are installed and maintained at many shipwrecks to prevent anchor damage.
Outside of the sanctuary, moorings at some wreck sites are maintained by local volunteers in cooperation with the Wisconsin Historical Society.