I had the unique pleasure of spending a week by the seaside a few months back. After doing a bit of walking to and fro on various sandy shores, my thoughts began to become somewhat melancholy in nature. None more so then after spending the afternoon on a small island off of the coast. I don't know if the locale caused it, or if it's something deep within our created being, but outside of awe, the other overriding emotion I experienced when surrounded by the sea was sorrow.
One thing that has always intrigued me about the literary giants, like Tolkien and Lewis, was their fascination with the sea and songs about the sea. For example, in The Voyage of the Dawn Treader by Lewis, it was in essence the song of the sea that drove the hounourable mouse Reepicheep to hunt for his home, Aslan's country. Yes, his journey into that country was joyful, but it was also tinged with sorrow. How about Tolkien's Middle-Earth? Where the song of the sea called the Elves home, and once they heard that call, their hearts yearned constantly for those shores.