Marine City's Nautical Mile is about a half mile long and is also known as South Water Street. This charming area stretches along the St. Clair River waterfront in the city's downtown and includes important local and regional points of interest.

The area features shops, restaurants, and pubs interspersed with five city parks, all in the very walk-able downtown. The parks host a public beach, deep water swimming area, riverfront volleyball court and an amphitheater, among other park amenities, and play host to several festivals each year.

The area is also part of the city's Outdoor Maritime Museum which features historical and nautical artifacts on a self-guided tour. Other Nautical Mile points of regional importance and interest are the Peche Island Rear Range Light (lighthouse), and the cathedral-like Holy Cross Catholic Church, one of the several historically designated structures in Marine City.

The Nautical Mile also hosts several of Marine City's well known antique shops; more are located along the adjacent shopping area on Broadway. Recent years have brought the addition of riverfront loft living to the Nautical Mile; these residences join a handful of private homes also located along South Water Street.