In order to provide funds for the purposes of this article, there are hereby authorized to be sold and issued bonds of the state not exceeding $3,500,000.00 in aggregate principal amount, under and subject to the provisions hereinafter set forth. The bonds shall be designated as inland waterways improvement bonds of the state. The bonds shall be general obligations of the state, for payment of the principal of and interest on which the full faith and credit of the state are hereby irrevocably pledged. The bonds may be issued from time to time in one or more series, shall bear an appropriate series designation, shall be in such form and denominations and of such tenor and maturities, shall bear such rate or rates of interest payable in such manner, may contain provisions for redemption prior to maturity, and may contain other provisions not inconsistent herewith, all as shall be set forth in an order or resolution of the department; provided, that the first installment of principal of the bonds of each series must mature not later than 10 years from the date of such series and the last installment of principal of the bonds of any series must mature not later than 30 years from such date; and, provided further, that any of the bonds having a stated maturity more than five years after its date shall be made subject to redemption at the option of the state at the end of the fifth year after the date of such bond and on any interest payment date thereafter under such terms and conditions as may be provided in the order or resolution whereunder such bond is authorized to be issued. The bonds shall be signed in the name of the state by either the facsimile or manually subscribed signatures of the Governor or the director of the department, and the Great Seal of the State, or a facsimile thereof, shall be affixed thereto or engraved, lithographed or imprinted thereon and attested by either the facsimile or manually subscribed signature of the Secretary of State; provided, that the signature on the bonds of any one of the said officials shall be subscribed manually thereon. The bonds may be in either bearer or registered form, either as to principal or interest or both. Interest on the bonds shall be payable semiannually, interest on coupon bonds being evidenced by interest coupons attached thereto, each of which coupons shall be authenticated by the facsimile signature of the State Treasurer imprinted thereon. Bonds issued in coupon form may be exchanged for fully registered bonds or bonds registered as to principal only. Coupon bonds and registered bonds shall be interchangeable; and upon issuance of a coupon bond for a registered bond, all matured and unearned coupons on said bond shall be by the State Treasurer first clipped from said bond and then cancelled. Regulations for the registration of bonds and for interchange of registered and coupon bonds shall be set forth in the order or resolution authorizing the issuance of such bonds. The State Treasurer shall maintain a record of all of the bonds issued hereunder, and shall maintain a separate record of all of the bonds that are registered, including a record of the names and addresses of the registered holders thereof. No order or resolution providing for the authorization or sale of any of the bonds shall become effective until approved by the Governor. The action of the department in adopting an order or resolution authorizing the sale of any of the bonds, and the action of the Governor in approving such order or resolution, shall be conclusive evidence that the funds to be derived from the bonds so authorized to be sold are actually needed at the time for the purposes for which bonds are herein authorized to be issued and that the proceeds of such bonds are intended only for such purposes.