Ocean/sea

The ocean is a continuous body of salt water that covers more than 70 percent of the Earth's surface. Ocean currents govern the world's weather and churn a kaleidoscope of life. ... The oceans hold about 321 million cubic miles (1.34 billion cubic kilometres) of water, which is roughly 97 percent of Earth's water supply.

Some geographers point to the Age of Discovery and suggest that the seven seas represent the Atlantic, Pacific, Arctic, and Indian Oceans, as well as the Mediterranean Sea, the Caribbean, and the Gulf of Mexico.

Around 70% of the Earth's surface is covered by oceans. The world's oceans contain enough water to fill a cube with edges over 1000 kilometres (621 miles) in length. Ocean tides are caused by the Earth rotating while the Moon and Sun's gravitational pull acts on ocean water.