The conversation between human and AI assistant.
[|Human|] What are the primary breathing apparatuses for scuba
[|AI|] The most common breathing apparatus for Scuba Diving is an open circuit single hose 2-stage demand regulator connected to a single gas cylinder.  A less common apparatus is a Closed Circuit or Semi-Closed rebreather.
[|Human|] 
What are the primary breathing apparatuses for scuba