Mighty Mac Swim

The Mighty Mac Swim is a 4.2-mile open water swim across the Straits of Mackinac organized by Jim Dreyer on Labor Day (7 September 2015) in Grand Rapids, Michigan. It also serves as the Michigan Open Water Championship. Participants are called Mighty Mac swimmers. It is 12th highest grossing charity swims in the world, raising US$432,000 in its inaugural year...

The Straits of Mackinac is the narrow waterway separating the U.S. State of Michigan's Lower Peninsula from its Upper Peninsula. It connects two of the Great Lakes, Lake Michigan and Lake Huron. The Straits of Mackinac is a major shipping lane providing passage for raw materials and finished goods.