DIVING GLOSSARY · Underwater science
Depth
Vertical distance below a reference surface, usually the water surface in recreational diving.
Explore the idea in context
Definitions are a starting point. These lessons connect the word to examples, illustrations and further reading.
Know your equipment
Gauges and units
Distinguish cylinder pressure from depth.
Read lesson →Know your equipment
What a dive computer knows
Distinguish measurements, settings and modelled information.
Read lesson →Underwater science
Pressure and depth
Explain why pressure changes below the surface.
Read lesson →Planning your dive
Depth and environment
Look beyond a single depth number.
Read lesson →Introductory definition · Instructor review pending.