A few days ago I went for a hike in the waters of a river. I was wearing waders like the ones you see in the following picture:
(source: directindustry.com)
I don't understand why the pressure I perceived on my legs when the water was 1 meter deep was far greater than that I had ever experienced before at the same depth. Maybe it has to do with the greater surface exposed to the water by the waders?
I added additional considerations below. For the sake of transparence I did not remove my initial idea which I consider no longer fully correct.
I think it is partially a perceptional problem. The pressure, i.e. force per area is depdendend on the depth of water in this case, and it doesn't matter much, if you are naked or if you wear waders.
But if you wear waders, the pressure is implied on the surface of your clothes, not on your skin. Your clothes will now dent to give in to the pressure, until they reach your skin which will resist the pressure by applying counterforce. As the waders can't reduce their surface, they will apply the pressure only at distinct places of your body. Where the clothes don't touch you, you will encounter only the air pressure at normal level. You can feel then the different pressure values (100 kPa vs. 110 kPa) on closely located parts of your skin. This will give you an increased sensation.
Furthermore, the sum of the forces on your waders is slightly greater than it was if you weren't wearing anything. This sum of forces is concentrated on the parts of your skin touched by your clothing.
Update
As I underwent my STCW 95 Basic Safety Training I had the opportunity to experience the wader phenomenon in full extent on my whole body. And I came up with another reasoning.
It is not a primarily perceptional effect! And it is difficult to explain.
You are in contact with your waders over a limited part of your body's surface. That is because your waders will warp and fold leaving parts of your legs uncovered. Your lower body now has now areas where the rubber exerts the surrounding water pressure on your skin and intermittent areas where it can't. The static pressure on that air filled gaps is, of course, only at an insignificant lower pressure than at water surface. If we assume a water depth of 50 cm, the difference between touched and untouched skin is 5 kPa.
This leads to a dislocation of body fluids resulting in an increased pressure. (I'm not yet 100% sure about that yet)
More important is the pressure difference which can be felt clearly, because it exerts additional lateral forces inside body tissue.
"Perceived" is the operative word here. Perception is subjective and pressure is hard to perceive objectively without a measuring device.
Hydrostatic pressure experienced by a body submersed to a height $h$ under water is given by:
$p=p_0+\rho gh$, with $p_0$ atmospheric pressure, $\rho$ the density of the water and $g$ the gravitational acceleration constant.
But due to the stiffness of the waders and the pressure $p$ acting on them the experience of wading with and without waders can be quite different. But this perceived effect is not due to greater surface exposed when wearing waders.
