TDI/SDI

Technical Diving International claims to be the largest technical diving certification agency in the world, and one of the first agencies to offer mixed gas and rebreather training.

Scuba Diving International is a Scuba training and certification agency. It is the recreational arm of Technical Diving International, a technical diver training organization. SDI is a member of the United States RSTC, the RSTC Canada and the RSTC