The area of operation of this part shall be:

(1) The dynamic dune fields on the barrier islands of this state as determined by reference to Code Section 12-5-232. Such determination shall be made by the permit-issuing authority on the basis of site inspection and evaluation of other pertinent information as provided for in subsection (d) of Code Section 12-5-239;

(2) The submerged shoreline lands of this state from the seaward limit of this state's jurisdiction landward to the dynamic dune fields or to a line projected from the westernmost point of the dynamic dune field on the southern end of a barrier island, to the westernmost point of the dynamic dune field on the northern end of the adjacent barrier island to the south; and

(3) If an area has dynamic dune fields as defined by Code Section 12-5-232, and marshlands as defined by Code Section 12-5-282, it is subject to the jurisdiction of this part and Part 4 of this article. In the event of a conflict between this part and Part 4 of this article, the commissioner shall determine which part shall apply so as to best protect the public interest.