Step-by-step explanation:
imagine a column of water of 1 m² that starts at the surface of the ocean, which goes straight down 700m.
You need to calculate the pressure induced by only the column of water.
Please understand that the total pressure is found by adding the pressure of the column of water AND that of the pressure of the atmosphere.
p = F/A
p = pressure in Pa
F = Force in N
A = area in m²
To calculate the Force that gravity has on that column of water, you simply use:
F = m * g
where g = 9.81 kgm/s²
So first you need to calculate the mass of the column sea water with a density of 1.024*10³ kg/m³