Westerink develops high resolution heterogeneous unstructured mesh, multi-physics, multi-scale hydrodynamic codes and models for the hydrodynamics of the coastal ocean and has successfully transitioned these to practitioners for a wide range of applications including the analysis and design of major flood control projects and coastal ocean water level forecasting systems. Westerink has pioneered the successful use of global to channel scale highly heterogeneous unstructured mesh coastal ocean models with mesh resolution varying by up to four orders of magnitude. This encompasses the optimization of algorithms; development of high performance codes in vector and parallel computing environments; the linkages of circulation models to weather and short wind wave models; model verification, validation, and uncertainty quantification; and the application of codes to oceans, continental shelf regions, estuaries, rivers, and coastal flood plains. Westerink is the co-developer, with Rick Luettich of the University of North Carolina at Chapel Hill and Clint Dawson of the University of Texas at Austin, of the widely used ADCIRC finite element based shallow water equation code. ADCIRC has evolved into a community based coastal hydrodynamics code with wide ranging applications within academia, government, and the private sector worldwide. The U.S. Army Corps of Engineers, the Federal Emergency Management Agency and the National Oceanic and Atmospheric Administration all use ADCIRC in support of coastal water level and flooding analyses and forecasts.