What is this standard about?
This document specifies requirements and test methods for divers’ watches and for saturation divers’ watches for use in deep diving (see Annex A which deals with watches for saturation diving). It applies to divers' watches designed to withstand diving in water at depths of at least 100 m and equipped with a secured measuring system to indicate the diving time, which is visible in darkness. Moreover, it indicates the marking which the manufacturer is authorized to apply to them.
BSI recommends this version of standard for organisations operating in or with the UK. The ISO edition is available here if required.