Calculate forces and centre of pressure on submerged surfaces. Consider the underwater hatch in the scenario pictured below: surface 1 m 2 m The hatch is rectangular and has a height of h = 2m and a width of b = 3m and does not run to the surface. Find the force needed to be applied at the top of the hatch to keep it closed. The fluid the hatch is submerged in is water with density 1020kgm.