Ala. Const. art. XI, § 213.12

Bonds or other securities issued by or on behalf of the Alabama state docks department shall not constitute a debt of the state within the meaning of Section 213 of this Constitution, as heretofore or hereafter amended, or any similar provision of this Constitution supplemental to, or superseding, said Section 213, as so amended, if by their terms such bonds or securities do not constitute a charge on the general credit or tax revenues of the state, but are payable solely from any or all of the revenues from any or all of the state docks facilities wherever situated (whether of [or] not such facilities were in existence or owned by or on behalf of the state at the time such bonds or securities were issued) or from sources other than state taxes, licenses or appropriations; provided, however, that the proceeds of any fee, tariff or charge (regardless of how denominated or calculated) collected by the Alabama state docks department in connection with the operation of the state docks facilities wherever situated shall be considered revenues from such facilities within the meaning of this amendment.