Probably photographed at Pensacola, Florida, in 1914. The Navy seaplane C-3 (redesignated AB-3 in March 1914) is in the background, with a thirteen-star boat flag flying from its port forward wing strut. This photograph was mounted on Mustin's certificate as U.S. Navy Air Pilot No. 3, issued in January 1915 with a 1 June 1914 date of precedence. See Photo # NH 105734-KN for a view of this certificate. In January 1918, after the Naval Air Pilot designation was merged with the Naval Aviator designation, Mustin was officially listed as Naval Aviator No. 11. U.S. Naval History and Heritage Command Photograph.