The dock board shall have authority, either alone or jointly with any similar body, to petition any interstate commerce commission, railway commission, or any like body or any federal, municipal, state or local authority, administrative, executive, judicial or legislative, having jurisdiction in the premises, for any relief, rates, charges, regulations or action which in the opinion of said body may be designed to improve or better the handling of commerce in and through the said harbor or port, or improve terminal or transportation facilities therein. It may intervene before any such body in any proceeding affecting the commerce of said harbor or port and in any such matters, the board shall be considered, along with other interested persons, one of the official representatives of the district in which said harbor or port is situated. The board shall have the authority to promote maritime and commercial interests of the harbor or port by the proper advertisement of its advantages and by the solicitation of business, through agencies established within or without said harbor or port within the United States or in foreign countries; and it shall endeavor to bring to the attention of the people of Nebraska, and of other states which may be properly served by the harbor or port, the economical advantages to be derived from the use of the harbor or port and its facilities.