Any port commission existing under the provisions of Article 3 of Chapter 7 of this title, and any other port commission or port authority now or hereafter constituted by law which has not expressly been granted such powers, may, in addition to all powers now or hereafter vested in it by law, exercise all powers and authority granted to county port authorities or county development commissions under Sections 59-9-15 through 59-9-35, which sections are hereby incorporated herein by reference, and may in addition to such powers acquire, own, operate and maintain gas, electric, water, sewerage or other public utility systems or pipelines and easements necessary thereto. In the event that a joint agreement cannot be consummated jointly with the board as provided in this chapter, the boards of supervisors of any county, or the governing authority of any municipality, or both acting jointly, may issue revenue bonds of such county or municipality, or both, acting jointly, as provided by section 59-7-311. Such revenue bonds may be issued without an election on resolution of the board of supervisors, governing body of the municipality, or both acting jointly, and shall not be subject to any limitation as to amount, and shall not be included or computed in the statutory limitation of indebtedness of any such county or municipality.

All leases executed by such port commissions or port authorities for port, harbor, commercial or industrial improvements, and all structures and all improvements and other permanent facilities erected, installed or located by such lessees, or their successors or assignees within the limits of any port, harbor or part thereof, may be free and exempt from all state, county and municipal ad valorem taxes if so stipulated in such lease, and for such period as may be fixed in such lease, not to exceed such periods of time as are now authorized or may be hereafter authorized by law.