The most popular of all specialities. Ideal for repetitive dives or to explore a wreck in 25m, for example. Diving on air with a higher oxygen percentage, therefore less nitrogen intake, puts you on a safer side and gives you more bottom time allowance. In the classroom your instructor will explain the relation between enriched air and pressure and how it has effect on your dive depth, for example. You will learn how to set your computer, mark and analyze your tank, analyze your cylinder and many things more.