art 4 Power to give general directions as to use of the harbour, etc.
(1) The Company may, in accordance with the requirements of article 5, give directions for the purpose of promoting or securing conditions conducive to the ease, convenience or safety of navigation, the safety of persons, the protection of property, and the prevention or amelioration of environmental harm in the harbour. (2) A direction under this article may apply— (a) to all vessels or to a class or type of vessel; or (b) to persons designated in the direction; or (c) to the whole of the harbour or to a part; or (d) at all times or at certain states of the tide; and every direction under this article shall specify the extent of its application in relation to the matters referred to in sub-paragraphs (a), (b), (c) and (d). (3) The Company may amend or revoke a direction given under paragraph (1). (4) For the purposes of this article, “environmental harm” means significant harm to the health of living organisms or other interference with the ecological systems of which they form part.