Madison Reef is a series of submerged rock shoals about 1.65 miles (2.65 kilometers) long and one mile (1.6 kilometers) offshore of Madison in New Haven County, Connecticut.[1] It is between four and seventeen feet (1.21 and 5.18 meters) deep, and separated by channels of deeper water. Charles Reef is to the south and west. A cable passes through the reef on the seafloor.[2]