The purpose of Scientific diving (SD) is science.
It is needed (1) - to support research and education and (2) - for the protection and conservation of the natural and cultural environment. It is neither recreational nor commercial diving.
SD exists in a health and safety framework that involves certified scientific divers, diving officers, scientific project leaders, heads of laboratories, administrators and legislators.

Diving is a highly-productive, cost-effective research tool that supports underwater science and archaeology through efficient and targeted sampling, quantitative survey, quantitative observation, making in situ measurement, undertaking impact studies, performing ecological analyses, evaluating new techniques, mapping underwater areas, profiling subtidal geology/geochemistry, and accurate deployment/retrieval of underwater apparatus.