In the summer of 1958 "Acacia's" home port was changed to Port Huron, Michigan, where a new berth was built for her. The city spent $10,667 on the dock. The change in home port did not fundamentally change the ship's mission. She was responsible for 145 aids to navigation in the Port Huron area. She continued to break ice in the Saint Claire River, and during several winters participated in "Operation Coal Shovel" to break ice between Toledo, Ohio and Detroit for the coal ships supplying power plants and industries in Detroit.