Why is that so many of us are drawn to the ocean... to the sound of tumbling waves and the sights and smells of the sea?It captivated the likes of Melville, Shakespeare and Byron. Whether to view it from the shore, out on the waves, or under the surface, people flock to the ocean. Mike Williams explores literature and science to discover what it is about the sea that is so compelling. He speaks to Hanli Prinsloo, a free-diver, from Cape Town in South Africa.(Image: Two men walk into the sea, under a sunny sky. Credit: AFP/Getty Images)