Part 3 specifies the training activities and competencies required for the training and accreditation of divers who are required to work safely and competently using self-contained underwater breathing apparatus (SCUBA) to depths of 30 m; using surface-supplied underwater breathing apparatus (SSBA) to depths of 50 m; and on sites with surface compression chambers present or within a convenient distance. Such qualification is the minimum required by regulatory authorities who are responsible for the control of off-shore diving, e.g. oil and gas exploration. Requirements for training divers for restricted certification, where the diver's underwater work capabilities are limited, are included.