Experimental tests in marine Labs have some difficulties such as expensive instruments, lack of equipment, and time-consuming procedures. However, one of the well-known strategies to investigate different phenomena is numerical simulations. A study of marine structure interaction with waves is significantly dependent on appropriate wave modeling. Accordingly, researchers are seeking to develop proper numerical wave tanks (NWTs) in predicting the interaction of marine structures with waves. In the present book, after an introduction and CFD formulations of the NWTs, we presented major issues related to numerical wave tank modeling. Afterward, different scenarios for modeling NWTs are proposed in the open-source CFD package of OpenFOAM. The source codes of NWTs solvers are also presented in the book's Appendix. This book can be appropriate guidance for researchers and engineers in the context of marine engineering and coastal, ports, and marine structures engineering.