Large bodies of water are an integral part of nature and, thus, are of high interest for interactive 3D applications, e.g., computer games and virtual environments. We present a new scheme for real-time wave simulation in large-scale water environments with physics-based object interaction. In addition to a fast and realistic liquid representation, our method focuses on the creation of plausible detailed waves caused by moving boats. We expand the well-known wave equation by applying it to moving grids to simulate an apparently limitless body of water. Additionally, we present a fast, particle-based boat simulation, which is coupled to water simulation. Importantly, most parts of our method can be implemented efficiently on GPUs. We demonstrate the visual realism and performance of our approach with several experiments using different boats and other floating objects, achieving high frame rates on a desktop PC.