The theme of the 4th International RoboBoat Competition, sponsored by The Association for Unmanned Vehicle Systems International (AUVSI) Foundation and the Office of Naval Research (ONR), was “The Four Elements.” Teams of students designed and built autonomous surface vehicles (ASVs) that faced challenges involving earth, air, fire and water. The competition was held at The Founders Inn and Spa, Virginia Beach, VA, June 8-12, 2011 and included 15 teams representing colleges and universities around the world.