The equilibrium position of each body is described by three translational and three rotational components of the center of gravity of the body, with respect to the origin of the fixed reference axes (FRA). To move a body towards equilibrium requires a number of iterative steps, where in each step the total stiffness matrix and the force vector are re-calculated. In general, the stiffness matrix is nonlinear.

The computed equilibrium configuration may be used as a starting point for subsequent frequency domain or time domain hydrodynamic analyses carried out by Aqwa. It is also used as an input to the static and dynamic stability computations.