The moves come in response to what company officials call "difficult conditions in the global marine market and economy." "The three plants near Knoxville have recently completed a production furlough, which has helped reduce our overall marine pipeline, but the global marine market remains in a severe downturn because of the weakening economies here and abroad and anxious consumer sentiment," Brunswick Chairman and Chief Executive Officer Dustan E. McCoy said through a statement released Tuesday. "These conditions have led to the difficult decision to mothball the Riverview facility." A total of 14 North American Brunswick boat plants have been have closed, mothballed or sold since 2006, officials said. Sea Ray boats have been made in Knoxville since 1959. The company was acquired by Brunswick in 1986.