A sea is a large body of salt water surrounded in whole or part by land. More broadly, “the sea” is the interconnected system of Earth’s salty, oceanic waters—considered as one global ocean or as several principal oceanic divisions.
The sea moderates Earth’s climate and has an essential role in the water, carbon, and nitrogen cycles. It has been traveled and explored since ancient times, while the scientific study of the sea—oceanography—dates broadly from the voyages of Captain James Cook to explore the Pacific Ocean between 1768 and 1779.
The word “sea” can be used to refer to one or more of the Earth’s most significant water bodies. It is used interchangeably with “ocean” in American English but not in British English, where “the sea” refers to the seafloor and “sea” is only used as a synonym for “seawater” in general.
Explore the Arabian Sea’s pivotal role in global trade, its dynamic climate, and the diverse marine life that thrives within its tropical waters.
Explore the key distinctions that define seas vs oceans, from size and depth to their unique marine ecosystems and geographic features.