"It's like a big mound of white water rolling in, taking buildings down, trees, cars, people. It's never just one wave; it's always a series of waves. When you go to the beach and see surf, you know that there's not going to be just one wave that day. There's wave after wave after wave. Well it's the same thing with a tsunami. There may be a dozen waves spread out over two or three hours. So, nothing at all like the waves you surf and absolutely nothing that you could survive if you were out there, trying to surf a regular swell after a tsunami struck. Try to bear in mind that after that first tsunami wave washes in, it's going to pick up everything in its path. It's going to pick up rocks and trees and houses covered with roofing iron, and it's going to suck that all out back to sea and the second wave is going to have all that in it," explains Dr. Walter Dudley.