Harb. & Nav. Code, § 3919

The State Treasurer shall on Controller’s warrants duly drawn for that purpose, invest the moneys in the Harbor Bond Sinking Fund in the purchase of the bonds of the United States, or of the State of California, including any bonds authorized, issued and theretofore sold under authority of this part or of the several counties, municipalities, school districts, or other public agencies of the State of California, which bonds shall be kept in a proper receptacle, appropriately labeled; but he shall keep on hand a sufficient amount of money in the sinking fund with which to pay the principal and interest on such of the state bonds as the same become due. The State Treasurer may only purchase such bonds authorized and issued under authority of this part with moneys in the sinking fund as have been theretofore sold.

Interest accruing upon investment made from moneys in the Harbor Bond Sinking Fund shall be deposited in the respective accounts thereof from which the money invested was derived unless otherwise required under any resolution providing for the issuance of revenue bonds to be credited to the San Francisco Harbor Improvement Fund.