The pressure on the submarine increases. This is because pressure in a fluid increases with depth. As the submarine goes deeper, the height (and therefore the weight) of the column of water above it increases, exerting a greater force on the submarine's surface area.
As the submarine descends, the pressure on it increases.
Pressure within a fluid is caused by the weight of the fluid particles above. The deeper an object goes, the greater the height of the column of fluid above it. This taller column of water has more mass and therefore a greater weight. This increased weight acts on the same surface area of the submarine, resulting in a higher pressure. The relationship is described by the equation p = hρg, where p is pressure, h is depth, ρ is density, and g is gravitational field strength. This shows that pressure (p) is directly proportional to depth (h).
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