Dreyer's swim near the Michigan-Canada border was to raise money for Habitat for Humanity, but he said it had other symbolic meaning given the situation in Detroit, which has filed for bankruptcy protection.
"What I really wanted to show is that even though there's a lot of financial pain in the state of Michigan and nobody's felt more pain than the city of Detroit we don't have to sink with the weight of our burdens," he told reporters after finishing.
Dreyer ended his swim at Detroit's Belle Isle, located on the Detroit River across from Canada. He had expected to finish Tuesday after about 30 hours, but he said waves along the way 2-3 feet during the day and 3-4 feet at night slowed him down.
"When you're pulling a ton of bricks into the whitecaps that's a big wave," Dreyer said.
Dreyer has made direct crossings of the five Great Lakes.