Underwater acoustical imaging is fast becoming a popular option for ocean exploration. However, it is very challenging and expensive to conduct elaborate experiments to validate the performance of algorithms developed for underwater imaging and array designing, which makes the simulation of underwater environment necessary. Besides acoustical imaging, any Sound Navigation and Ranging (SONAR) signal processing applications such as object detection, image enhancement and classification require a proper simulation tool which models the underwater scenario as realistic as possible. In this paper, we propose to use the k-Wave toolbox for modelling underwater target for acoustical 2D and 3D imaging. The accuracy of the data obtained from k-Wave is analysed by computing structural similarity index of the reconstructed 3D image with the reference 3D image.