USS Mikawe (SP-309) was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1919. Mikawe was built as a civilian wooden-hulled motorboat of the same name in 1916 by Defoe Boat and Motor Works at Bay City, Michigan. The U.S. Navy purchased her from her owner, Thomas H. Gill, for $12,500 (USD) on 10 August 1917 for World War I service as a patrol vessel and commissioned her the same day as USS Mikawe (SP-309). On 24 April 1919, Mikawe was transferred to the United States Coast and Geodetic Survey, in which she served from 1920 to 1939 as USC&GS Mikawe.