Numerical investigations of hydrodynamic interactions between side-by-side barges, in terms of gap free-surface response and forcings, are carried out using the analysis framework developed in Part I. The barges are assumed to be rigidly fixed. Two sets of investigations are carried out, both covering a range of incident wave frequencies. The first set examines the influence of gap width on free-surface response between two rectangular barges with square bilge corners. Following the analysis framework, a selected set of viscous simulations are carried out and the resulting flow field data are used to quantify the viscous losses through skin friction and vortex shedding. These quantified losses are converted into dissipation coefficients for use in a modified linear potential flow code, to investigate a larger set of loadcases compared to the viscous simulations. Gap free-surface responses and forcings predicted using the code are compared with results from viscous simulations and discussed. Based on the results, an efficient solution strategy for modelling side-by-side hydrodynamic interactions is proposed. The second set of investigations studies the effect of bilge curvature on the hydrodynamic interactions between the two barges and demonstrates that the framework can also be used to study variations in hull geometric parameters.