If I put a couple of lead bricks on my foot, there would be a definite sensation of a heavy, perhaps even painful, force. Calculating the pressure for $20 kg$ of lead over a $100 cm^2$ area of my foot, I get about $20 kPa$.
Now I stand underwater in a pool. If my foot is $2 m$ below the surface, then the hydrostatic pressure would be $\text{density} \times \text{depth} \times \text{gravity}$, or $20 kPa$. Same as above. But in this case I wouldn't feel any pain or high pressure on my foot. Why the difference in sensation when under water, even though the pressure is the same in both cases?
Best Answer
You should feel the water pressure too, but much weaker. The difference is that water pressure is isotropic and does not "deform" the body in one direction but does it uniformly - uniformly shrinking it from all directions.
Consider the animals that live very deep. They are like "baloons filled with water" (and we to some extent too). I guess the pressure does not hurt. It is deformation of the body that hurts. If you consider baloon filled with water it is pretty easy to deform it (hence cause pain) preserving the volume, but much more difficult to uniformly shrink it (as this changes the volume)
IMHO very interesting physical question