Part 3 specifies the training activities and terminal objectives 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 20 m; using surface-supplied underwater breathing apparatus to depths of 50 m; and on sites with surface compression chambers present or within convenient distance. Such qualification is the minimum required by regulatory authorities who are responsible for the control of on-shore diving, e.g. oil and gas exploration.