PADI (Professional Association of Diving Instructors)

The largest recreational scuba certification agency in the world, founded in the United States in 1966 and known for its modular course system.

PADI, the Professional Association of Diving Instructors, is the largest scuba certification agency in the world. It was founded in the United States in 1966 by John Cronin and Ralph Erickson, and today it certifies the majority of new recreational divers worldwide. If you learned to dive at a resort or a typical dive shop, there is a good chance your first C-card was a PADI Open Water Diver card.

PADI is known for a highly standardized, modular teaching system. Courses follow a fixed sequence of knowledge development, confined water skills, and open water dives, which makes training consistent whether you certify in Thailand or in a quarry at home. The recreational ladder runs from Open Water Diver through Advanced Open Water Diver and Rescue Diver up to Divemaster and instructor ratings, with a large catalog of specialty courses in between.

PADI certifications never expire, though after a long break most operators will ask for a refresher course or a check dive before taking you out. The agency also runs a large conservation arm through the PADI AWARE Foundation, and its eLearning platform lets students finish all theory online before ever visiting the dive center, which is now the most common way the course begins.