Dana was the primary Danish research vessel for almost 40 years. It was built in 1937 and served research purposes until 1980. On the first cruise into the North Atlantic in 1938 it was discovered that the ship was unsuited for its purpose, as it was not sufficiently stable to allow scientific work. It was returned to the shipyard and extended by 8 metres (26 ft) in 1939. During the Second World War (1940-1945) the ship was kept and maintained in Copenhagen harbour, but with vital engine parts removed and thus never seized by the German occupation force.