How do divers experience pressure underwater?

Divers experience pressure underwater due to the weight of the water above them, which increases with depth.

When a diver descends into the water, they are essentially going deeper into a fluid environment. This fluid, in this case water, exerts pressure on the diver. This pressure is not just from the water directly above the diver, but from all directions. This is because fluids, including water, exert pressure evenly in all directions.

The pressure experienced by divers underwater is directly proportional to the depth they are at. This is due to the weight of the water above them. The deeper they go, the more water there is above them, and therefore the greater the weight and the greater the pressure. This is why divers often feel a squeezing sensation on their ears and body as they descend deeper into the water.

In addition to the pressure from the water, divers also experience atmospheric pressure. This is the pressure exerted by the weight of the air in the atmosphere above the water. Even at the surface of the water, before they have even started to descend, divers are already experiencing this atmospheric pressure.

To give you an idea of how much pressure divers experience, for every 10 metres they descend in freshwater, the pressure increases by approximately 1 atmosphere. This means that at a depth of 10 metres, the pressure is 2 atmospheres (1 from the water and 1 from the air), at 20 metres it's 3 atmospheres, and so on.

It's important for divers to understand and manage this pressure. If they ascend too quickly, the decrease in pressure can cause dissolved gases in their body to form bubbles, leading to a potentially serious condition known as decompression sickness or 'the bends'.