The problem with the visualization of the flow of water is the simplification of the facts that have occurred over the years. Water doesn't really flow downhill. Water flows in the direction of the resultant force vector of the sum of all the forces acting upon it. I know that I just went off the 'deep end', so to speak. I got this lesson from my college engineering courses in fluid mechanics. You combine that with the courses in statics and dynamics and you can get a feel for just why water really behaves like it does. Understanding water is essential for a seaman, it's what keeps you alive sometimes. To me the fact that the rains fall, rivers flow to the seas, and that the seas can be curved around the globe have all proceeded from a comprehensive education in the characteristics of water. That water covers the majority of the earth, flat or round. There is no real mystery why Louisiana isn't flooded, although New Orleans needs some significant flood walls to keep the streets dry. I know, real understanding is a high entry bar for most. It's also irrelevant and not needed for those who live inland. However for those who dare to educate themselves in the subject of water, you can eventually understand why the globe earth model is the only thing that has ever worked.