Within the boundaries of the seashore, the Secretary may acquire submerged land, land, waters, and interests therein by donation, purchase with donated or appropriated funds, or exchange, except that property owned by a State or any political subdivision thereof may be acquired only with the consent of the owner. The Secretary may acquire by any of the above methods not more than four hundred acres of land or interests therein outside of the seashore boundaries on the mainland in the vicinity of Biloxi-Gulfport, Mississippi, for an administrative site and related facilities for access to the seashore. With the concurrence of the agency having custody thereof, any Federal property within the seashore and mainland site may be transferred without consideration to the administrative jurisdiction of the Secretary for the purposes of the seashore.
With respect to improved residential property acquired for the purposes of sections 459h to 459h–10 of this title, which is beneficially owned by a natural person and which the Secretary of the Interior determines can be continued in that use for a limited period of time without undue interference with the administration, development, or public use of the seashore, the owner thereof may on the date of its acquisition by the Secretary retain a right of use and occupancy of the property for noncommercial residential purposes for a term, as the owner may elect, ending either (1) at the death of the owner or his spouse, whichever occurs later, or (2) not more than twenty-five years from the date of acquisition. Any right so retained may during its existence be transferred or assigned. The Secretary shall pay to the owner the fair market value of the property on the date of such acquisition, less their  fair market value on such date of the right retained by the owner.
As used in sections 459h to 459h–10 of this title, “improved residential property” means a single-family year-round dwelling, the construction of which began before January 1, 1967, and which serves as the owner’s permanent place of abode at the time of its acquisition by the United States, together with not more than three acres of land on which the dwelling and appurtenant buildings are located that the Secretary finds is reasonably necessary for the owner’s continued use and occupancy of the dwelling: Provided, That the Secretary may exclude from improved residential property any marsh, beach, or waters and adjoining land that the Secretary deems is necessary for public access to such marsh, beach, or waters.
The Secretary may terminate a right of use and occupancy retained pursuant to this section upon his determination that such use and occupancy is being exercised in a manner not consistent with the purposes of sections 459h to 459h–10 of this title, and upon tender to the holder of the right an amount equal to the fair market value of that portion of the right which remains unexpired on the date of termination.