World War II: Sinking of the prison ships Cap Arcona, Thielbek and Deutschland by the Royal Air Force in Lübeck Bay.
A prison ship, often more accurately described as a prison hulk, is a current or former seagoing vessel that has been modified to become a place of substantive detention for convicts, prisoners of war or civilian internees. While many nations have deployed prison ships over time, the practice was most widespread in seventeenth and eighteenth century Britain, as the government sought to address the issues of overcrowded civilian jails on land and an influx of enemy detainees from the War of Jenkins' Ear, the Seven Years' War and the French Revolutionary and Napoleonic Wars.