4 Extension of meaning of“work” and“at work”
For the purposes of these Regulations and of Part I of the 1974 Act, the meaning of“work” and“at work” shall be extended, in relation to the provision of first-aid and other medical assistance, the provision of advice in connection with health, and the provision of information in connection with all the foregoing, so that all persons employed or self-employed are treated as being at work whether or not they are on duty, if they are on–
(a) an offshore installation;
(b) a vessel engaged in pipeline works; or
(c) a vessel from which any of the following activities in connection with an offshore installation are being carried on, that is to say construction, reconstruction, alteration, repair, maintenance, cleaning, demolition, dismantling and any activity immediately preparatory thereto.