 Following the armistice, she was returned to the jurisdiction of the Department of Commerce with the rest of the Lighthouse Service under an Executive order of 1 July 1919.On the morning of 23 July 1920, while supplying Passage Island Light Station, Lake Superior, Michigan, the "Amaranth" struck the rocks under water at the extreme southwesterly point of the island, breaking the shoe and rudder, with the total loss of the latter.Repairs were made by the Port Arthur Shipbuilding Company, Port Arthur, Ontario.