Davis graduated with Bachelor of Science degree and was commissioned Ensign on June 7, 1913. He was subsequently attached to the battleship USS "Kansas" and cruised the east coast for the next several months. Davis took part in the patrols in the Gulf of Mexico during the Veracruz Expedition in summer 1914 and then participated in another series of patrols in the Caribbean, protecting life and property during a revolution in Haiti in late 1915.