The increasing susceptibility of coastal infrastructure to natural hazards (e.g., tropical cyclones) exacerbated by climate change necessitates a rethinking of adaptation solutions beyond traditional hard structures like seawalls. In the twenty-first century, there has been an increasing push towards the use of natural ecosystems, referred to as natural and nature-based features (NNBFs), for coastal protection rather than solely relying on human-made defenses. One of the most common examples of NNBFs is that of coastal vegetation. In particular, vegetation such as mangroves or salt marshes can be highly effective at protecting communities from coastal hazards like tsunamis or extreme wave impact while maintaining natural processes and conserving ecological systems. Even oyster reefs have been demonstrated to be effective at shielding shorelines from large waves. This chapter will discuss how reductions in wave height can be predicted based on the properties of submerged vegetation.