What are the seven seas?

Medieval European and Arabic literature often spoke of the Seven Seas. Which seven seas are intended depends on the context. The "Seven Seas" was a commonplace phrase in many ancient literatures before it was taken up by the Greeks and Romans; it appears in a translation of one of Enheduanna's hymns to Inanna (Hymn 8), written about 2300 BC in Sumer (Meador 2001). The number seven has ancient magic of its own in many traditions, informing many groupings of seven. "Seven" as an indefinite number remains for a long time synonymous with "several", as in the Greek Seven Seas. In Greek and Western culture, the "seven" seas were arbitrary and changed over time, varying depending upon the part of the world and the period of time. However, they were usually seven out of the following list of nine bodies of water: