Built in 1929 at A&P Tees, Middlesbrough as a whale catcher Kos 4 for the Hvalfangerselskapet A/S. She was hired by the Royal British Navy in July 1940 for be used as a minesweeper but she had a Norwegian crew. A year later she was renamed Dröbak. After the Second World War was she on 30 June 1946 given back and retained her original name With a gross tonnage of 248 tons. In 2007 still existing as the Norwegian Fru Petrell. In 2013 mentioned as ‘dead’. IMO 5042156, deadweight 406 tons and gross tonnage 292 tons. According to maritime-connector ex-KOS 4 renamed 1958 Guro, renamed 1982 Lisund and renamed 1974 Fru Petrell.
