The title is intended to catch the attention of people in the era of internet where information and misinformation abound. Using examples from the sea and the ocean, I hope to convince people that just like what the author of "The World is Flat" argued, there have been lots of opportunities, and indeed real examples that people are working together like never before.
"The Earth is Flat," on the other hand, is based on pseudoscience, and is held by a few who may not even be serious; the idea is circulating in internet, nevertheless. Whereas it is easy to tell the difference between the two "flats" mentioned above, it may not be in more normal questions. "How is the seawater blue?" is one such practice.