23.—(1) Article 4 applies to a removal activity carried on by a person referred to in paragraph (2) for the purpose of removing anything causing or likely to cause obstruction or danger to navigation.
(2) The persons are—
(a)a conservancy authority (within the meaning given by section 313(1) of the Merchant Shipping Act 1995(1);
(b)a harbour authority;
(c)a lighthouse authority;
(d)a person having powers under any enactment or statutory order to work or maintain a canal or other inland navigation, including a navigation in tidal water.