The Tec 45 subcourse of the DSAT Tec Diver course introduces Tec 40 divers to the first stages of full, technical deep decompression diving. Certified Tec 45 divers are qualified to make multistop decompression dives that employ EANx and oxygen for accelerated decompression. The expectation is that a Tec 45 diver intends to continue on in technical diving. Accordingly, the course not only develops the knowledge and skills to make open circuit technical dives as deep as 45 metres/145 feet, but also begins developing the knowledge and skills the diver will need at the Tec 50 level and beyond.

The Tec 45 course consists of three knowledge development sections, three practical applications sessions and four training dives.

Participant prerequisites: Certified as a Tec 40 diver or qualifying certification from another training organization. For the purposes of this level, a qualifying technical certification is one that qualifies the student to make decompression dives to 40 metres/130 feet using air and EANx using open circuit scuba equipment. 18 years old, 50 logged dives (12 deeper than 18 metres/60 feet using EANx, at least 6 deeper than 30 metres/100 feet (with or without EANx).