I remember as a child working furiously with my brother to erect a sand castle fast enough during low tide so we could enjoy it before the high tide began its work of destroying our youthful attempts at engineering. Even as children we had a respect for the power of the ocean. We knew our sand castle was a bit of fantasy that was temporary fun, but I am not so sure we have the same notion when it comes to seawalls or other structures erected along sand, gravel or cobble shorelines. Hurricane Sandy reminds us just how powerful the ocean is and how vulnerable nearly any structure is that we put within its reach. With its reach now expanding, what can be done?