Whenever it is determined by the Public Utilities Commission that ferry transportation for persons and property between the mainland and the islands in Casco Bay located within the limits of the City of Portland and the Town of Cumberland can no longer feasibly be provided by private operators at rates established by the Public Utilities Commission, the Department of Transportation shall take such means as necessary to provide the service, either through contract with private operators or by acquiring and operating the necessary facilities as provided in this section.   [PL 1981, c. 456, Pt. A, §88 (NEW).]