Semmes was born in Memphis, Tennessee, on 8 April 1913. He graduated from the United States Naval Academy in 1934. As a lieutenant commander, Semmes took command of the destroyer USS Picking (DD-685) during World War II on 12 August 1944 and continued as her commanding officer until August 1945. During his time in command, Picking escorted troop transports during the Leyte campaign in October 1944 – narrowly missing action in the Battle of Leyte Gulf – and escorted amphibious forces and rendered gunfire support to troops ashore during the Luzon campaign in January 1945.