(a) In this section, "port authority" means a navigation district located wholly or partly in the security district, and created or operating under Section 52, Article III, or Section 59, Article XVI, Texas Constitution.
(b) If a port authority is located in the district, the executive director, or a person designated by the executive director, serves as a director. If more than one port authority is located in the district, the executive director, or a person designated by the executive director, of the port authority with the largest territory inside the district serves as a director.