ISO 15618-1:2016 specifies essential requirements, ranges of qualification, test conditions, acceptance requirements and certification for the qualification testing of welder-diver performance.ISO 15618-1:2016 is applicable for hyperbaric wet welding on steel.The recommended format for the certificate of qualification testing is given in Annex A.During the qualification test, the welder-diver may be required to show adequate job knowledge of the welding processes, materials and safety requirements for which he is to be qualified. Information on these aspects is given in Annex B.The welding processes referred to in this part of ISO 15618 include those fusion welding processes which are designated as manual or partly mechanised welding. It does not cover fully mechanised and fully automatic processes (see 5.2).This part of ISO 15618 applies to all new qualifications from the date of issue.However, ISO 15618-1:2016 does not invalidate previous welder-diver qualifications made to former national standards or specifications, providing the intent of the technical requirements is satisfied and the previous qualifications are relevant to the application and production work on which they are employed.The certificate of qualification testing is issued under the sole responsibility of the examiner or examining body.