Deep diving

Deep diving has different meanings depending on the context. Even in recreational diving the meaning may vary:

In recreational diving, a depth below about 30 metres (98 ft), where nitrogen narcosis becomes a significant hazard for some divers, may be considered a "deep dive".

For some recreational diving agencies, Deep diving, or Deep diver may be a certification awarded to divers that have been trained to dive to a specified depth range, generally deeper than 30 metres (98 ft). However, the Professional Association of Diving Instructors (PADI) defines anything from 18 metres (60 ft) to 30 metres (100 ft) as a "deep dive" in the context of recreational diving (other diving organisations vary), and considers deep diving a form of technical diving.

In technical diving, a depth below about 60 metres (200 ft) where hypoxic breathing gas becomes necessary to avoid oxygen toxicity may be considered a "deep dive".

In professional diving, a depth that requires special equipment, procedures, or advanced training may be considered a deep dive.