A physically-based computational model, which implements a variety of technologies to real-time simulation of the ocean surface dynamics and waves-body interaction, is proposed. The method uses data from experimental observation of the real ocean, stochastic description of irregular wind waves, inverse non-uniform fast Fourier transform mathematical tool, unstructured grid representation for changeable water surface and complex geometry of the floating object, reasonably full and accurate immersed rigid-body dynamics, fast and stable algorithms for solving the equations of motion. The integrated mathematical model combines the proven approaches, which are adapted and modified for stated goals. The developed approach does not impose restrictions on complexity of the immersed body configuration. The implemented algorithms allow to perform an interactive simulation on a desktop computer using high resolution surface meshes without loss of frame rate. Some examples are considered to demonstrate the abilities of the model to simulate the interaction of partially submerged body (rescue boat) with wind-generated irregular fluctuations of the water surface in the real-time mode.