Breakwaters are structures built along coastlines to protect harbors, marinas, and shorelines from the impact of waves and erosion. They are typically made of large rocks or concrete and can be either floating or fixed to the seabed. By absorbing and deflecting wave energy, breakwaters help create calmer waters for boats and reduce the risk of flooding in coastal areas. These structures can also promote sediment accumulation, which can help maintain beaches and prevent erosion. However, breakwaters can alter local ecosystems and may require careful planning to minimize environmental impacts. Proper design and placement are essential for their effectiveness and sustainability.