 Seagoing services in the 1910s was partly as captain and division commander of torpedo boats.Ehrensvärd was commanding officer of the Destroyer Division in 1919 and from 1923 to 1924.He was then head of the Communications Department at the Naval Staff from 1927 to 1929, captain of the in 1929 and was head of the Operations Department at the Naval Staff from 1929 to 1932 and was promoted to captain in 1933.