The growing occupation and development of low lying coastal areas in combination with the projection for increased flood susceptibility due to rising sea levels and storm climatology suggests a mounting necessity to advance our understanding of coastal and ocean processes and improve our risk assessment and forecasting abilities. Presented herein is a treatise on the application and model response sensitivities of coastal and ocean models that solve the diverse and multi-length-, -time-, and -energy-scales of astronomical tides, hurricane storm surge, coastal inundation, and wind-waves. This Gulf of Mexico region specific study included: 1) a performance assessment in terms of skill and execution speed for leading coastal and ocean models at simulating astronomical tides, hurricane storm surge, coastal inundation, and wind-waves; 2) an investigation of the National Weather Service's operational forecast model, SLOSH, with respect to its internal wind model performance and sensitivity to domain size; 3) an evaluation of coastal and ocean model response sensitivity to mesh resolution and wave bottom friction formulation; 4) an analysis of the spatial and temporal contributions of wave radiation stress gradients and non-linear advection terms and a scaling of other components of the shallow water equations; and 5) an examination of the mechanistic role that anthropogenic features, discharge, and wetlands play in the generation and propagation of riverine storm surge. In order to facilitate the improvement of existing and the transition of additional models to operational use, this study seeks to clarify many of the assumptions that are generally made with coastal and ocean modeling, particularly by addressing model sensitivities to aspects of numerical approach, mesh design, parameterization, and physical components. Tidal harmonic analyses, hindcasts of Hurricane Ike (2008) and Rita (2005), and a probabilistic ensemble of a suite of historical and hypothetical storms were performed to address both low and high energy processes as well as a diverse range of storm characteristics.