Das Boot is a German television series produced by Bavaria Fiction for Sky One and a sequel to the film of the same name. Based on Lothar-Günther Buchheim's book and its sequel, Die Festung, the series focuses on the World War II events at sea on various U-boats, in the Battle of the Atlantic and the Allied invasion of Italy, and on land, in Europe and America.Seasons 1-4 have been released between 2018 and 2023.