Fill a 3-meter water pipe and place it on the sea's surface. According to the diameter of the water pipe, which is 15 cm, we can calculate the mass and height of the water column in the water pipe when the bottom is connected to the sea level.

 

Unfortunately, I didn't become a villain. The sudden increase in pressure in the pipe will only affect a small area under the pipe. At least I became a nightmare of those 7.07 square millimetres of stones under my feet.