The Department of Transportation may operate a special charter service to Hurricane Island in Knox County, or to ports added or to be added by legislative enactment. The operation of this charter service shall not interfere nor curtail in any way the schedule of the Maine State Ferry Service to ports named in this section or to ports added or to be added by legislative enactment. [PL 1987, c. 402, Pt. A, §148 (AMD).]