This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Employment Income Manual

Tax treatment of workers in the North Sea and other offshore oil and gas fields: meaning of exploration or exploitation activities

Section 41(2) ITEPA 2003

Exploration or exploitation activities means activities carried on in connection with the exploration or exploitation of so much of the sea bed and subsoil and their natural resources as is situated in the United Kingdom or a designated area. This definition is fairly wide; it covers not only workers employed on pipelaying vessels, oil and gas rigs and other offshore installations, but also those engaged in ancillary or support work. As regards divers and diving supervisors see the Employment Status Manual (ESM).