How does water pressure work?


I understand that the deeper you dive into the ocean the more pressure you will face. I also know it’s a gradual change in pressure. But how is that pressure created?

In: 5

1L of water weights 1kg. The more water you put on top of you, the heavier it feels. That’s pressure.

The weight of the water on top of you just adds up. Its like stacking bricks or rocks on yourself

You’re driving below 100s of feet of water, each gallon weighs ~8lbs that adds up on top of your body and is why we need pressurized ships to explore the very bottoms of oceans.

Each gallon of water weighs approximately 8lbs. The deeper you go the more gallons of water are on top of you therefore more weight is on you.

Whenever you are in the water you really have a column of water on top of you all the way to the surface, you are basically being crushed by that water as if you were carrying a bunch of rocks on your head.

The deeper you go the more water is above you and the greater the weight. This weight is what we call pressure.

It might seem strange but the same is true for air as well. At sea level the pressure around you is 1 “atmosphere”, 1 atmosphere is equal to about 15 pounds per square inch, meaning that the air above you presses down on you with 15 lbs of pressure on each square inch of your body.

That pressure is just the weight of all the water that’s now above you, pushing down on you due to the Earth’s gravity.

We are adapted to air pressure such that we don’t feel it in our day-to-day. We become aware of it when it changes though — Denver, Colorado is about a mile above sea level. Because it’s so high up, there there’s less atmosphere above you, pushing down on you. That translates to Denver only having about 85% the air pressure as at sea level, and people who travel there sometimes have to take time to acclimate to the “thin” air. Going deep underwater is the opposite — in addition to the weight of the atmosphere above you, you are also adding the weight of water.

What weighs more, 1 ton of feathers or 1 ton of bricks?

The deeper you go, the more water is pushing against you from all sides. That increased weight pressing against you is pressure.

Basically even Water being a Liquid it still has Weight, while underwater you are receiving the force of that weight in your whole body (As in your whole body is submerged). And as to how this force works it’s Action and Reaction, the act of submerging makes the water have a reaction to that.

Lets replace water with people.

If you have a pile of 10 people and you’re the person on top, you have no weight on top of you.

If you are the 5th one down, you have the weight of 4 people on top of you and it’s probably not going to be very comfortable.

If you’re the one on the bottom, you have the weight of 9 people on top of you, and at this point you should probably start rethinking your life and how you ended up in this situation.

Water works the same way. Water has weight to it, so the further down you go the more water there is above you pressing down.

It usually starts when you notice a friend drinking water. Then they say “come on, have some” , but you know better. Next you see all your friends drinking water, and you feel left out of the group. Eventually you give in to the pressure and drink the water. Before you know it you feel like you’ll die if you don’t get your next drink of water. The water pressure got to you.


A similar post from a while back. (More answers there.)

To add to the weight of the water above you there is also the weight of the atmosphere sitting on top of the water surface. And air is far from weightless.

The pressure comes from the weight of the water above the point where you are measuring/feeling the pressure. Water is heavy. Think about carrying a 5 gallon bucket of water; now think about all those gallons are above you when you are diving underwater!