This is a list of notable professional and amateur explorers who have personally explored the underwater environment and contributed towards expanding the knowledge and understanding of that environment. The list may include archaeologists, wreck divers, treasure hunters, biologists, marine geologists, geophysicists, ocean engineers, oceanographers, crew of exploration submersibles, cave divers and surveyors of the underwater topography, but these categories are not exclusive.
Robert F. Marx (1936–2019), pioneer underwater archaeologist, prolific author
John Mattera (born 1962), discoverer of the pirate ship of Joseph Bannister, and the Golden Fleece, and cave diver who mapped cave systems in the Dominican Republic
Agnes Milowka (23 December 1981 – 27 February 2011), Australian cave diver, underwater photographer and author