4.—(1) Without prejudice to regulation 5 of the General Duties Regulations, and subject to paragraphs (2) to (4), and regulation 5(1), these Regulations apply in relation to United Kingdom ships.
(2) Where—
(a)a ship is being used in the course of public service activities or activities for the purposes of the civil protection services; and
(b)characteristics peculiar to those activities inevitably conflict with a provision of these Regulations,
that provision does not apply in relation to that ship to the extent of that conflict.
(3) To the extent that a provision of these Regulations does not apply in relation to a ship because of paragraph (2), there is in relation to that ship a duty on the employer to ensure, so far as is reasonably practicable, the health and safety of workers carrying out work at height.
(4) This regulation (other than paragraph (1)) and regulations 5, 21 and 23 apply in relation to ships other than United Kingdom ships when they are in United Kingdom waters.
(5) In paragraph (2)—
“civil protection services” includes the fire and rescue and ambulance services and search and rescue services provided by any other person;
“public service activities” includes the activities of the armed forces, HM Coastguard, HM Revenue and Customs, immigration officers, police, prison officers and the security and intelligence services.