Technical Diving International
Technical Diving International (TDI) is the largest technical diving certification agency in the world. As one of the first agencies to provide training in mixed gas diving and rebreathers, TDI is seen as an innovator of new diving techniques and programs which previously were not available to the general public.
TDI specializes in more advanced Scuba diving techniques, such as diving with rebreathers and mixed breathing gases, such as Heliox.
TDI was founded in 1993 by Bret Gilliam and Mitch Skaggs after a split away from International Association of Nitrox and Technical Divers (IANTD) in 1993.