Linked from
The 65 pages that link to Hydrostatic pressure, each with the reason it gives.
PressureBroader topic: The weight of fluid above a point makes pressure rise with depth.
HydrostaticsBroader topic: Its increase with depth is the central pressure law of hydrostatics.
Pascal (unit)Broader topic: Its depth-dependent values are calculated and reported in pascals.
Water pressureBroader topic: Water pressure rises with depth when water is still.