The Detroit River is only 0.5–2.5 miles (0.8–4.0 km) wide. It begins with an east-to-west flow from Lake St. Clair, but curves and runs north to south. The deepest portion of the Detroit River is 53 feet (16.2 m) in its northern portion.

The river is 28 miles long and serves as the international border between Canada and the United States, connecting Lake St. Clair and the Upper Great Lakes to Lake Erie, and is one of the busiest waterways in the world. Heavy traffic and the urbanization on its shores led the Detroit River to become very polluted.

The Detroit River serves more than 5 million people with drinking water, recreation and cultural opportunities. It is the busiest port in the Great Lakes, with 8,000 commercial vessels each year carrying more than 100 million tons of cargo.

That water this infamous is typically safe for swimming is a lucky byproduct of the Detroit River's size and swift current. From Belle Isle Beach, the water often appears still, and when the wind blows from the west, the river seems to flow backward into Lake St.