The master of every vessel shall give notice to the wharf manager of his intention to discharge or load before such work is commenced. No goods, livestock, or other material of any sort whatsoever shall be discharged or shipped, except at such times and places, and in such order and mode as may be directed and deemed expedient by the wharf manager for the proper working of any wharf or jetty. Cargo discharged without permission of the wharf manager being first obtained shall not be deemed to be in the custody of the Board, nor shall the Board be held responsible for any loss or damage that may accrue to such cargo from any cause whatever.