Diver training is really a life-long event. Every dive can teach you something. When you begin to learn there are several qualification agencies to choose from. Our qualifications page gives brief notes on them. See also our account of the PADI fast track course and the article on diving safely.
If you have a diving project involving underwater mapping, see our technology page. We also have a guest article on the differences between SCUBA Diving International (SDI) and Professional Association of Dive instructors (PADI).