Lake Michigan alone has swallowed up more vessles than the Bermuda Triangle. Diving just the wrecks between Michigan, Chicago and Wisconsin is popular I am told.
I believe (but have not checked my facts) that The Great Lakes together comprise the largest fresh water body on the planet. Accordingly, and even if not the largest, they have tremendous impact on global weather and environments.
The lake is a couple block from me and part of a pond system even closer. There are days when Lake Michigan is almost tropical in color and others where it looks nothing short of dark gray, cold and mean. We had giant swells caused from the West end of the recent storm that met up with Sandy. I remember one winter storm where the trees along the lake had horizontal icicles about 3 to 4 feet long. Should have had a camera with me.
When I lived here last, Lake Michigan got declared an ocean bay through a series of technical qualifications so that a team from Chicago could enter The America's Cup Race.