On another forum, someone asserted that most of the old ancient Mesopotamian kingdoms were established as "watershed kingdoms" meaning that they were intentionally fixed on bodies of water or at locations below the high-tide mark. Washington, D.C. is on (en and on in Spanish are the same) the Potomac. Psalms 24:2 came to mind.
If I recall correctly, "the sea" in the Book of Revelations represents the people or a 'multitude or nation of people'.For He on the seas hath founded it, And on the floods He doth establish it. (YLT)
Related:'The waters that thou didst see, where the whore doth sit, are peoples, and multitudes, and nations, and tongues;' Revelations 17:15 (YLT)
Sea or Waters (Index to Symbols, Understanding Prophetic Symbols And Apocalyptic Language Of The Bible By Comparing Symbols From Old And New Testament Prophecies)