Scientific diving is the use of diving techniques by scientists to study underwater what would normally be studied by scientists on land. Scientific divers are normally qualified scientists first and divers second, who use diving equipment and techniques as their way to get to the location of their fieldwork. Underwater archeology, marine biology and geology are examples of sciences pursued underwater. Some scientific diving is carried out by universities in support of undergraduate or postgraduate research programs. In the United States scientific diving is permitted by the Occupational Safety and Health Administration to operate under an alternative consensual standard of practice that is maintained by the American Academy of Underwater Sciences.

To be able to avail itself of the Scientific Diving Exemption the institution under whose auspices the work is carried out must meet four tests:

1. The Diving Control Board consisting of a majority of active scientific divers must have autonomous and absolute authority over the scientific diving program's operations.

2. The purpose of all projects using scientific diving is the advancement of science; therefore, information and data resulting from the project are non-proprietary.

3. The tasks of a scientific diver are those of an observer and data gatherer. Construction and trouble-shooting tasks traditionally associated with commercial diving are not included within scientific diving.

4. Scientific divers, based on the nature of their activities, must use scientific expertise in studying the underwater environment and, therefore, are scientists or scientists in training.

Government bodies such as the United States Environmental Protection Agency and the UK Environment Agency carry out scientific diving to recover samples of water, marine organisms and sea, lake or riverbed material to examine for signs of pollution.

Equipment used varies widely in this field, but surface supplied equipment though quite uncommon in the UK is growing in popularity in the U.S. The short number of dives made by scientific divers in normally quite shallow water, and the UK governmental regulations that make surface supplied equipment cumbersome, when combined with a need for easy transportation make surface supplied gear uneconomic and undesirable for UK scientists to use.