The word ‘oceans’ implies the large water bodies of the world, namely the Pacific, Atlantic, Indian, and Arctic, as well as the Antarctic oceans where we find icebergs. Smaller seas are separated from the oceans by island chains or underwater ridges, which are called ‘bordering seas’. These include the North Sea, the Baltic Sea, the Mediterranean Sea and the Caribbean Sea. The bordering seas and the oceans have some common features: both contain salty water and restless seabeds. But there are also differences in the variety of plants and animals living in them and the storm tides-the tides that lash the coast of the North Sea are hardly found along the Pacific coast.