The second USS Saco was a yard tug in the United States Navy during the 1920s.

History
United States
Name	USS Saco (YT-31)
Builder	A.C. Brown and Son, Tottenville, New York
Laid down	1912
Acquired	30 September 1918
Stricken	22 October 1926
Fate	Sold, 3 May 1927
General characteristics
Type	Tug
Displacement	119 long tons (121 t)
Length	90 ft (27 m)
Beam	24 ft 8 in (7.52 m)
Draft	8 ft (2.4 m)
Speed	8 knots (15 km/h; 9.2 mph)

The steam tug Alexander Brown was built in 1912 for the Aransas Dock and Channel Company, Aransas Pass, Texas, by A.C. Brown and Son, Tottenville, New York. She was acquired by the Navy on 30 September 1918 and designated SP-2725.

Purchased for use as a yard tug at the Naval Air Station Key West, she operated there as Alexander Brown until 24 November 1920, when she was renamed Saco and redesignated YT-31. Saco continued yard tug operations until struck from the Navy list on 22 October 1926. She was sold to N. Block and Company, Norfolk, Virginia, on 3 May 1927.