From: Dictionary of American Naval Fighting Ships, Vol. II p 347
The prized green gem stone.
The third Emerald (PYC--1), a yacht, was built in 1922 as Savitar by Consolidated Shipbuilding Co., Morris Heights, N.Y.; acquired by the Navy 25 October 1940 ; and commissioned 27 December 1940, Lieutenant (junior grade) Robert W. Graham in command.
After calling at Norfolk, Emerald arrived at Jacksonville, Fla., 13 February 1941 for patrol duty off the Florida coast, and served as harbor entrance control station in Saint Johns River between December 1941 and March 1942. Her last service was as examination ship at Key West, and on 31 May Emerald arrived at Miami, where she lay until decommissioned 11 August 1942. She was transferred to the Maritime Commission for disposal 13 November 1945.