The “Express Yacht” Isabel was turned over to the U.S. Navy two weeks prior to her launch at Bath Iron Works by John North Willys, head of Willys Overland automobile company. Retaining Willys’s name for her, the 1,045-ton (full load displacement) ship was commissioned on 28 December 1918 and given hull number PY-10. Able to steam at more than 28 knots when new, the Isabel was armed as a destroyer, with four 3-inch dual-purpose and two 3-inch/23-caliber antiaircraft guns, plus two twin 21-inch torpedo tube mounts and an outfit of depth charges. The yacht possessed a range of 6,000 nautical miles, making her ideal as a convoy escort; during World War I, while operating from French ports, she made four attacks on German submarines, including one in conjunction with the destroyer Reid (DD-21) on 18 March 1918 that gained the Isabel’s commanding officer a Navy Cross—although it later was found that the German submarine had escaped.
After a brief postwar stint as a recruiting ship on the Mississippi River and then as tender for the Navy flying boat squadron prior to its Transatlantic flight in 1919, the Isabel went into reserve at Philadelphia. She recommissioned in July 1921 after conversion to serve as flagship of the Yangtze River Patrol. Reaching Chinese waters that November, the Isabel operated until 1928 on the 1,700-mile navigable stretch of the Yangtze, wintering upriver at Hankow and based at Shanghai in the summer. The 245-foot ship then was assigned to the Asiatic Fleet and was based at Manila Bay for the next 13 years. On the opening day of hostilities with Japan, the Isabel was near-missed by eight dud Japanese bombs at Cavite and shot down one of her attackers. Again pressed into convoy escort service, she participated in the rear-guard defense of the East Indies and drove off a surfaced Japanese submarine with gunfire while rescuing survivors of a Dutch merchant ship in February 1942. From 7 March 1942, the Isabel was assigned to the U.S. Navy submarine base at Fremantle as escort and training ship. Sent homeward at the end of August 1945, she was decommissioned on 11 February 1946 and sold for scrap the next month, having been awarded one Battle Star for her World War II service.
The Isabel is seen above as first commissioned, in a complex segmented camouflage scheme and carrying the armament of a destroyer. Note the portside twin torpedo-tube mount, just abaft the boat davits, and the canvas-shielded lookout stations on both masts.
On duty in China in the early 1920s, the Isabel assumed a more yachtlike guise, with white hull and buff-colored stacks and superstructure and tall, stately masts; gone were the torpedo tubes, and a deckhouse with a canvas-roofed ceremonial area atop was added aft for diplomatic functions.