There more than 100 bodies of water in the world that are either officially named seas or commonly referred to that way. When someone talks about sailing the “seven seas,” which particular seven are they referring to?
It depends on who you ask, and when. A lot of the time, the term isn’t meant to be taken literally, and simply refers to all the seas and oceans of the world. According to the National Oceanic and Atmospheric Administration, though, ever since the term was first recorded in ancient Mesopotamia in a religious poem, different cultures have used the phrase for specific sets of bodies of water. In different places and at different times, it was applied to trade routes, regional waterways or the waters of far-away, exotic places.
The ancient Greeks, who introduced the term to the West, applied it to the Adriatic, Aegean, Black, Caspian, Mediterranean and Red seas and the Persian Gulf.
To Medieval Arabian geographers and explorers, the seven seas were the bodies of water they travelled on voyages to the Far East, which they called the Sea of Fars (the modern-day Persian Gulf), Larwi (Gulf of Aden and Arabian Sea), Harkand (Bay of Bengal), Kalah or Kalahbar (Strait of Malacca), Salahit (Singapore Strait), Kardanj (the Gulf of Thailand and the part of the South China Sea between Sumatra and Borneo), and Sanji (South China Sea).
Medieval Europeans, meanwhile, had a few different sets of seven seas that included the Adriatic, Aegean, Arabian, Baltic, Black, Caspian, Mediterranean, North and Red seas, as well as the Persian Gulf, Indian Ocean and Atlantic Ocean.
During the Age of Exploration and the European discovery of the Americas, some sailors began including New World waters into the group, so the seven seas included the Arctic, Atlantic, Indian and Pacific oceans, the Caribbean and Mediterranean seas and the Gulf of Mexico in different groupings.
The term is mainly used figuratively today, but if you wanted to keep it literal, says NOAA, the world has five major oceans—the Arctic, Atlantic, Indian, Southern (Antarctic) and Pacific—and the Atlantic and Pacific are cut into north and south divisions by the equator, giving you seven “seas” to sail.