Two thirds of our planet is covered with water. Every fragment of land, from the great continent of Eurasia to the tiniest Pacific island, has a shore. The total length of shorelines is huge. Yet the width is hardly measurable in comparison, it is often just a few yards.
Shores are strange places, being the edge of the land as well as the edge of the sea.
The sea level rises and falls with the tides, making the shore sometimes wet and sometimes dry. Winds drive unchecked across the open ocean and hit the coast with great force. As they blow, they whip up waves that endlessly crash into the land. No two stretches of shore are the same. Each is shaped by many variable factors, the tides, wind, water currents, temperature, climate, and the types of rock from which the land is made.