Revelation 18:17
Revelation 17:1 plainly declares that she sits upon many waters, and Revelation 18:17, 19 add related material through the mention of ships, sailors, and trading by sea. She sits, meaning that she rules, exercises her authority, operates, or is located, upon many waters. We cannot exclude the dual possibilities here of waters representing both peoples and literal waters. Please recall that this is a description of an end-time Babylon.
The ancient city of Babylon sat astride the Euphrates River, but the nation itself had relatively limited access to the sea. If God is describing the ancient nation, it is a poor application. By way of contrast, every nation of modern Israel except Switzerland sits on an ocean and has a multitude of deep-water seaports.
End-time Babylon has a large number of sea gates and is graced by great rivers and many large freshwater lakes. What this entire word picture in Revelation 17 and 18 describes is its political, military, economic, and geographic dominance. It is especially dominant worldwide in trade - so much so that Revelation 18:23 says that its merchants, not its priests, are called "the great men of the earth."
John W. Ritenbaugh
The Beast and Babylon (Part Ten): Babylon the Great Is a Nation