Beaches tend to develop gentle curves punctuated by sharp cusps. Long Tail Point in Green Bay. Beach terraces exposed by uplift near Santa Barbara, California. A wave-cut platform in tilted sedimentary rocks near Santa Barbara, California. Uplifted beach terraces south of San Francisco, California.
Breakwaters catch sand but also prevent it from replenishing the beach further downdrift.
Erosion downdrift accelerates, requiring the next property owner to build a breakwater until the entire shoreline is dotted with them, as on this beach in New Jersey. Tidal marshes like this along the shore of Chesapeake Bay look fragile but comparison of very old and modern charts sometimes shows that channels have not changed in centuries. Chesapeake Bay is an estuary and these flooded valleys in Maryland extend far inland. Erosion along the shore of Lake Michigan. Note also how incoming waves are bent, or refracted.