"Acacia's" first home port was Detroit, Michigan. Her primary mission was maintaining aids to navigation. Much of her activity was driven by the annual advance and retreat of heavy winter ice on the Great Lakes. Buoys were brought to port in the fall to prevent them from being damaged, sunk, or set adrift by ice. "Acacia" was reported to have picked up about 150 buoys from the Detroit River and nearby waters in ten days in December 1948. Buoys were cleaned, repaired, and repainted over the winter and redeployed by the ship in the spring.