Introduction
The Great Lakes are often referred to as inland seas, and once you spend time on them, it’s easy to understand why. Stretching across the border between the United States and Canada, they form the largest group of freshwater lakes in the world by surface area and hold nearly 20% of the planet’s fresh surface water.
For divers, they offer something even more unique — cold, freshwater conditions that have preserved thousands of historic shipwrecks, many of which remain remarkably intact beneath the surface.
A ship in harbor is safe,
but that is not what ships are built for.
— John A. Shedd
The Five Great Lakes
The Great Lakes consist of five interconnected lakes: Superior, Michigan, Huron, Erie, and Ontario.
- Lake Superior (depth 1,332 ft) is the largest and deepest, known for its cold temperatures and powerful storms, including the one that sank the Edmund Fitzgerald. It also sits at the highest elevation in the Great Lakes system.
- Lake Michigan (depth 992 ft), the only one located entirely within the United States, is home to a large concentration of well-preserved shipwrecks, especially along the Wisconsin coast, and connects to Lake Huron through the Straits of Mackinac.
- Lake Huron (depth 715 ft), including the Straits of Mackinac and much of its coastline, is another major hub for shipwreck diving and plays a central role in the movement of water through the system.
- Lake Erie (depth 210 ft) is the shallowest and warmest of the five, with the largest concentration of diveable shipwrecks in its deeper eastern basin, and sits at a lower elevation as the water continues to flow eastward.
- Lake Ontario (depth 801 ft) is the lowest in elevation and the outlet of the Great Lakes system, connecting to the Atlantic Ocean through the St. Lawrence Seaway. It is known for its deeper, well-preserved shipwrecks, including historic War of 1812 vessels such as the Hamilton and Scourge, which remain remarkably preserved.
A Freshwater System
Although they look like oceans, the Great Lakes are freshwater. This has a major impact on what happens beneath the surface. Unlike saltwater environments, where marine organisms and corrosion quickly break down wrecks, the cold freshwater of the Great Lakes slows deterioration significantly.
As a result, many shipwrecks still retain structural features like hull shape, cargo, and even interior details that would not survive in saltwater. This is one of the reasons Great Lakes shipwreck diving is considered some of the best in the world.
Shipwreck History
Over the past few centuries, the Great Lakes have been a major transportation route for cargo, raw materials, and passengers. With heavy traffic, unpredictable weather, and rapidly changing conditions, thousands of vessels have been lost. Storms, collisions, fires, and navigational challenges all played a role in these losses. Navigational tools and weather forecasting were far more limited than they are today, long before GPS, modern buoy systems, or real-time weather tracking.
Today, estimates suggest there are over 6,000 shipwrecks across the Great Lakes, with only a portion of them discovered and documented. Each wreck tells a story, not just of how it was lost, but of the era it belonged to.
Diving the Great Lakes
Diving in the Great Lakes is very different from ocean diving. Water temperatures remain cold for much of the year, and visibility can vary depending on location and conditions. Many wrecks lie at depths suitable for recreational divers, while others require technical training.
Because of the preservation conditions, divers often experience wrecks that feel like time capsules. It’s not uncommon to see intact decks, machinery, and cargo that offer a direct connection to the past.
For those prepared for the environment, the Great Lakes offer a unique combination of history, exploration, and underwater clarity that is difficult to find anywhere else.
For additional information about the Great Lakes, you can explore resources such as the Michigan Sea Grant’s Great Lakes Fast Facts.