The first captain of the icebreaker was (1875–1931). After his death Captain Fricis Veidners (1883–1942) and Pēteris Maurītis (1887–?) succeeded in command. After the Soviet occupation of Latvia in 1940 the ship was nationalized. At the end of August 1941 "Krišjānis Valdemārs" took part in Soviet evacuation of Tallinn to Kronstadt, but struck a naval mine on August 28 and sunk. "Krišjānis Valdemārs", loaded with cargo, was bombed and sunk in the Gulf of Finland by Junkers Ju 88 aircraft of Kampfgeschwader 77, Luftwaffe.