The seventh USS Niagara (CMc-2/PG-52/AGP-1) was an auxiliary ship of the United States Navy during World War II. Niagara laid down on 14 November 1928 as the steel-hulled civilian yacht Hi-Esmaro by the Bath Iron Works, Maine, launched on 7 June 1929, and delivered on 20 August. She was purchased by the Navy on 16 October 1940 from Mrs. Hiram Edward Manville of New York City. Converted to a coastal minelayer at the New York Navy Yard, and designated CMc-2 on 31 October 1940, the ship was renamed Niagara, on 12 November 1940, and reclassified as a patrol gunboat, PG-52 on 15 November 1940. She commissioned at New York on 20 January 1941, Lt. Edwin W. Herron in command.