(1) Subject to the provisions of this section, no person, except in pursuance of a licence granted under section 2 below and in accordance with the terms of that licence—
(a) shall dump substances or articles in United Kingdom waters; or
(b) shall dump substances or articles in the sea outside United Kingdom waters from a British ship, aircraft, hovercraft or marine structure ; or
(c) shall load substances or articles on to a ship, aircraft, hovercraft or marine structure in the United Kingdom or United Kingdom waters for dumping in the sea, whether in United Kingdom waters or not ; or
(d) shall cause or permit substances or articles to be dumped or loaded as mentioned in paragraphs (a) to (c) above.
(2) Subject to subsections (3) to (5) below, substances and articles are dumped in the sea for the purposes of this Act if they are permanently deposited in the sea from a vehicle, ship, aircraft, hovercraft or marine structure, or from a structure on land constructed or adapted wholly or mainly for the purpose of depositing solids in the sea.
(3) A discharge incidental to or derived from the normal operation of a ship, aircraft, vehicle, hovercraft or marine structure or of its equipment does not constitute dumping for the purposes of this Act unless the ship, aircraft, vehicle, hovercraft or marine structure in question is constructed or adapted wholly or mainly for the purpose of the disposal of waste or spoil and the discharge takes place as part of its operation for that purpose.
(4) A deposit made by, or with the written consent of, a harbour authority or lighthouse authority, for the purpose of providing moorings or securing aids to navigation, does not constitute dumping for the purposes of this Act.
(5) A deposit made by or on behalf of a harbour authority in the execution of works of maintenance in their harbour does not constitute dumping for the purposes of this Act if it is made on the site of the works.
(6) Subject to subsections (7) to (9) below, any person who contravenes subsection (1) above shall be guilty of an offence and liable—
(a) on summary conviction to a fine of not more than £400 or to imprisonment for a term of not more than six months or to both ; or
(b) on conviction on indictment, to imprisonment for not more than five years, or a fine, or to both.
(7) It shall be a defence for a person charged with an offence under subsection (6) above to prove—
(a) that the substances or articles in question were dumped for the purpose of securing the safety of a ship, aircraft, hovercraft or marine structure or of saving life ; and
(b) that he took steps within a reasonable time to inform the Minister that the dumping had taken place and of the locality and circumstances in which it took place and the nature and quantity of the substances or articles dumped,
unless the court is satisfied that the dumping was not necessary for any of the purposes mentioned above and was not a reasonable step to take in the circumstances.
(8) It shall be a defence for a person charged with an offence under subsection (6) above to prove—
(a) that he acted under instructions given to him by his employer, or
(b) that he acted in reliance on information given to him by others without any reason to suppose that the information was false or misleading,
and in either case that he took all such steps as were reasonably open to him to ensure that no offence would be committed.
(9) It shall be a defence for a person charged with an offence under subsection (6) above in relation to substances or articles dumped outside United Kingdom waters from a British ship, aircraft or hovercraft to prove that they were loaded on to it in a Convention State and that the dumping was authorised by a licence issued by the responsible authority in that State.