The Paul Tregurtha, a 1,013-foot freighter known as a “laker,” is believed to be the longest active vessel in the Great Lakes. Built in Toledo, Ohio, it was launched in 1981 and hauls coal and iron ore. Here, it is seen along the Detroit River in Detroit on Aug. 4, 2019. A battle is brewing between the shipping industry and environmentalists over efforts to extend ballast water regulations to “lakers” – freighters that do not leave the Great Lakes. Photo by Anthony Lanzilote / Bridge Magazine.