The idea
Water pressure increases with depth because there is more water above the point being considered. Total surrounding pressure also includes the atmosphere above the water. In physics, pressure is force distributed over an area, rather than simply another word for depth.
This relationship is a foundation for later learning about gas spaces and equipment. A classroom pressure diagram is not a dive profile or permission to reach a particular depth. The purpose here is to recognise the direction of change and the difference between a depth measurement and a pressure measurement.
More water above, greater pressure
Near the surface
Less water above
Further below
More water above
Deeper still
Greater surrounding pressure
Conceptual water column, not a dive profile. Total surrounding pressure also includes atmospheric pressure; no depth scale is shown.
Put it in context
| Idea | What it means | Question to explore |
|---|---|---|
| Depth | Distance below the surface | Where is the point being considered? |
| Water pressure | The contribution of water above it | How does increasing depth affect it? |
| Total pressure | Atmospheric plus water pressure | Which pressure is a calculation referring to? |
A QUICK KNOWLEDGE CHECK
Try it for yourself
A self-study check, not a qualification or skills assessment.
Words to know
- Pressure
- Force distributed over an area.
- Depth
- Vertical distance below a reference surface, usually the water surface in recreational diving.
- Absolute pressure
- Pressure measured relative to a vacuum, including the atmospheric contribution.
Sources & further reading
Primary references for the underlying concepts. The learning examples, questions and diagrams are original YouDive material.
OpenStax, College Physics 2e: 11.4 Variation of Pressure with Depth in a FluidSources checked 30 September 2026. Lesson awaits qualified instructor review.
This is an introductory self-study lesson. Learn and practise diving skills with a qualified instructor. Mascot art is illustrative, not an equipment-use diagram.