Linear Hydrostatics The Linear Hydrostatics model takes into account hydrostatic mean and restoring forces which are nearly linear in heave, roll and pitch. The mathematical details are described in the Theory. The Linear Hydrostatics model does not respect the Apply Gravity Force checkbox on the SIMO body model. Gravity forces are always applied (and not double counted) for bodies with a Linear Hydrostatics model, irrespective of this checkbox. (The checkbox may be removed in future versions of SIMA) The Linear Hydrostatics replaces Hydrostatic Stiffness Matrix which is deprecated from SIMA 5.0 onwards. Damping Matrix Hydrostatic Stiffness Matrix