Harbors and Navigation Code section 6830

The district shall be governed by a port commission, which consists of five members. Two commissioners shall be appointed by the board of supervisors of the county in which is located the largest proportion in value of the lands within the district. Two commissioners shall be appointed by the governing body of the municipal corporation, having the largest proportion in value of lands within the district. One commissioner shall be appointed by joint action of the boards of supervisors of any other counties located in the district.