The county board or the governing body of any incorporated city or village in the State of Nebraska may, and is hereby authorized and empowered, when in its judgment it is deemed expedient, to establish a board of public docks to be known as Dock Board of .......... (here insert name of county or municipality establishing such board) which shall be a body corporate and politic, and possess all the usual powers of a corporation for public purposes, and in its name may sue and be sued, purchase, hold, and sell personal property and real estate. Such board shall consist of seven members to be known as commissioners of public docks.