USS Shadow III (SP-102)

USS Shadow III (SP-102) was an armed motorboat that served in the United States Navy as a patrol vessel from 1917 to 1919. Shadow III was built as a civilian motorboat in 1916 by the Purdy Boat Company, at Miami, Florida. The U.S. Navy purchased Shadow III from Purdy on 12 June 1917 for use as a patrol boat during World War I. She was commissioned on 4 September 1917 as USS Shadow III (SP-102) with Ensign Charles D. Mack, USNRF, in command.

Shadow III patrolled the Florida coast off Miami during World War I. After the war, she acted as an aircraft crash boat for Naval Air Station Miami, Florida.

Shadow III was decommissioned at Miami on 25 January 1919. The Navy delivered her to the Parris Island Marine Corps Base at Parris Island, South Carolina, on 1 August 1919 for further non-commissiomned service.

In December 1919, Shadow III was taken to the Charleston Navy Yard at Charleston, South Carolina, for survey. She was sold on 5 August 1921 to Mike Letiff of Charleston.