The board of supervisors may manage the business of the district and promote the commercial interest of the harbor by advertisement of its advantages and by the solicitation of business within or without the district, in other states, or in foreign countries, through employees or agencies as are expedient, and it may organize, promote, conduct, and advertise programs of community recreation and the advantages of the district’s park and recreational facilities.

Nothing in this section authorizes revenues derived from tide and submerged lands granted in trust by the state to a district, or from lands acquired with those trust revenues, to be used by the district for any purpose other than for proper trust purposes on the granted lands, or for the acquisition, improvement, and maintenance of property adjacent to the granted lands when the property is necessary to further the purposes of the trust grant.