Pressure at any point in a fluid = ρ x g x h [KN/m²]

      where ρ = density of liquid [tonnes/metre³]

                g = 9.81 [metre/second²]

                h = distance of the point from liquid surface [metre]

(1)  Load acting on an immersed plate = Pressure x Area
                                                        = (ρ x g x h) x A [KN]

       where ρ = density of liquid [tonnes/metre³]

                 g = 9.81 [metre/second²]

                 h = centroid of the immersed area from liquid surface^* [metre]

                 A = immersed area of the plate [metre²]

(2)  Load taken by a stiffener of an immersed plate = ρ x g x h x A [KN]

       where ρ = density of liquid [tonnes/metre³]

                 g = 9.81 [metre/second²]

                 h = centroid of the immersed panel area from liquid surface
                    = depth of immersion of the plate divided by 2 [metre]

                 A = immersed area of the rectangular panel plate supported by
                       the stiffener
                    = width of panel x depth of immersion [metre²]

Centre of pressure from liquid surface

    =   2nd moment of area of immersed area about surface
             1st moment of immersed area about surface

    =    I + A(h)²   [metre]
             A(h)

     where   I   =   I _NA [metre⁴]
                     =   2^nd moment of area of the immersed area about
                          the neutral axis which is parallel to the liquid surface

                 A  =   immersed area [metre²]

                 h  =   position of the neutral axis from the surface [metre]
                     =   centroid of the immersed area from the liquid surface

Centroid of immersed area from liquid surface = Σ (A x y)
                                                                          ΣA

     where Σ(A x y) = Moment of area about liquid surface

                            = (A₁.y₁ + A₂.y₂ + A₃.y₃ + ....)

                        y_n = distance of centroid of each immersed area, A_n
                               from the liquid surface

                       ΣA = total immersed area