From: Dictionary of American Naval Fighting Ships, Vol.VIII p 568
Zircon
A semi-precious gemstone derived from the mineral, zirconium silicate.
Nakhoda -- a yacht built in 1929 by the Pusey & Jones Corp. at Wilmington, Del.--was acquired by the Navy from automobile body manufacturer, Mr. Fred J. Fisher, of Detroit, Mich., on 9 December 1940 ; renamed Zircon (PY--16) ; outfitted at the Brooklyn Navy Yard ; and commissioned on 25 March 1941, Lt. Comdr. Cornelius M. Sullivan in command.
Though assigned to New London, Conn., as an antiaircraft gunnery school ship specializing in machinegun training for officer trainees, Zircon also conducted inshore patrols and visited ports from New York to Casco Bay, Maine. Those duties continued until the fall of 1941, at which time she began making mail and dispatch runs between Portland, Maine, and Argentia, Newfoundland. In mid-February 1942, she was reassigned to the Eastern Sea Frontier and initially conducted patrols along the coast of New Jersey. Following extensive repairs in June, the converted yacht reported for duty with the Commander, Caribbean Sea Frontier, under whose auspices she escorted convoys between Guantanamo Bay, Cuba, and New York City. Zircon steamed back and forth between Cuba and New York--occasionally calling at some of the islands of the West Indies, notably Trinidad and San Salvador--until 1 March 1944. At that juncture, she received a temporary assignment to the Coast Guards weather patrol. Between March and November 1944, she operated out of Boston and plied the waters of the North Atlantic with the weather patrol. However, she continued to participate to some extent in the protection of New York-Guantanamo Bay convoys and of other mercantile traffic along the North American coast.
On 16 November 1944, Zircon reported for duty with the Commander, DD--DE Shakedown Task Group. That duty lasted until 7 December, when she was designated relief flagship for the Commander in Chief, Atlantic Fleet, based at Philadelphia. She served in that capacity through the end of World War II. In September 1946, she received orders to report to the Commandant, 6th Naval District at Charleston, S.C., to prepare for decommissioning and disposal. On 10 May 1946, Zircon was decommissioned at Charleston. Her name was struck from the Navy list on 5 June 1946, and she was turned over to the Maritime Commission for disposal on 17 October 1946. She was sold by the War Shipping Administration on 24 April 1947.