The county port and harbor commission shall have jurisdiction over the ports, terminals, harbors, channels, and passes leading thereto, and all vessels, boats, and wharves, common carriers and public utilities therein, using the same within the county. The board of supervisors of each such county electing to exercise the provisions of this chapter shall pay or cause to be paid into the port fund of said county a sum equal to one fourth of the sum paid into said fund under this chapter from the state tax levy and such payments shall be continued as long as there remains unpaid and outstanding any bonded indebtedness created by such board of supervisors as hereinafter provided. Any such board of supervisors shall provide the sum herein required either by appropriation from any available funds of the county or by the levy, in addition to all other county taxes, of a tax of two mills on the dollar of the assessed valuation of taxable property within such county upon which taxes for the general county fund are levied and collected. In case of a special tax levy as herein authorized, the tax collector of each such county shall set aside the avails of such levy and shall pay the same directly into the port fund of such county. However, no part of such two mill levy shall be reimbursable under the homestead exemption laws of the State of Mississippi.