The USS Ontario (AT-13) was a single-screw seagoing tug built by the New York Shipbuilding Company in Camden, New Jersey. Laid down on 23 November 1911 and launched on 11 April 1912, she was commissioned at the Philadelphia Navy Yard on 4 September 1912. Recognized as one of the finest naval tugboats of her time, Ontario featured advanced design and capabilities that supported fleet operations along the Atlantic Coast and in the Caribbean during her initial years. Throughout her service, Ontario primarily performed auxiliary duties, including port support, portering, and towing. With the onset of World War I, she played an active role in maritime defense along the U.S. East Coast, laying anti-submarine nets, patrolling for mines, and towing barges of crucial wartime supplies from 1917. Notably, she towed the schooner Charlotte W. Miller after a collision near New London, Connecticut, and assisted in salvaging the grounded merchant vessel Matanzas off Halifax. In late 1918, Ontario was deployed to European waters, joining the Atlantic Fleet Mine Force in Ireland, where she patrolled against enemy submarines and participated in clearing war remnants from minefields across Europe. After the war, she served as a station ship, rescue vessel, and flagship at American Samoa beginning in 1920, operating out of Tutuila for two decades. Her versatile service made her a prominent vessel in Samoa, inspiring local recruits and becoming a naval fixture. In 1941, she was converted from coal to oil and stationed at Pearl Harbor. During the Japanese attack on Pearl Harbor, Ontario engaged enemy aircraft with her machine guns, claiming to have downed one plane. She subsequently supported fleet operations in the Pacific theater, including the invasions of the Gilbert, Marshall, and Ellice Islands, and served as a yard tug at Ulithi during the final stages of World War II. She returned to the United States in December 1945, served briefly as a yard tug at Long Beach, California, and was decommissioned on 3 June 1946. Struck from the Naval Vessel Register in June 1946 and sold in 1947, the USS Ontario earned one battle star for her WWII service, marking a distinguished career spanning both world wars.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.