 Complete the following phrase:  Kauffman was assigned to the destroyer USS Hopkins under Lieutet Harold G. Bowen, stationed at Mare Island Navy Yard following a Boiler explosion. He was commissioned Ensign on 6 June 1910, after completing two years of service at sea then required by law. After a period of Hopkins repairs and service with the Reserve Fleet, he was appointed commanding officer of the Hopkins in November 1912. Kauffman was promoted to Lieutet junior grade on 6 June 1913 and commanded his ship until January 1914, when he was relieved by new commanding officer more senior in rank and transferred to the capacity of ships executive officer. He participated with the Hopkins in the naval operations in Mexican waters during 