HB 3243 modifies the governance structure of the Calhoun Port Authority by increasing the number of navigation commissioners on the board from six to seven. It introduces an at-large commissioner elected by all voters in the district, in addition to the existing six commissioners who represent individual precincts. The first election for this new at-large position will be held in May 2027, but until then, the governor will appoint an interim at-large commissioner to serve until the elected commissioner qualifies for the position. The bill also updates candidate qualifications, requiring that candidates for precinct seats reside in the precinct they seek to represent, while at-large candidates must reside anywhere within Calhoun County.