Cumberland Island National Seashore Wilderness Boundary Act of 2003

Cumberland Island National Seashore Wilderness Boundary Act of 2003 - Designates certain land (excluding specified roadways) in the Cumberland Island Seashore as a component of the National Wilderness Preservation System and names it the Cumberland Island Wilderness (the Wilderness). Directs the Secretary of the Interior (the Secretary) to include in the Wilderness specified land to be acquired and also certain other land once all prohibited uses on it have ceased. Directs that the Wilderness be administered by the Secretary in accordance with the applicable provisions of the Wilderness Act, with references to the Secretary of Agriculture in such Act where appropriate to be deemed references to the Secretary.

Allows: (1) persons with an existing right to utility service on Cumberland Island to retain such right in the Wilderness after the enactment of this Act; and (2) the Secretary to grant contracts, as deemed appropriate, for the provision of tours to visitors of the Cumberland Island National Seashore.