From the serpentine "Champie" of Lake Champlain to the venerable "Nessie" of Loch Ness, extraordinary-and un-explained-creatures of the deep have been reported in sightings throughout the twentieth century. Now, two of the world's leading cryptozoological investigators provide a globetrotting field guide to when, where, and what kind of mysterious aquatic beasts have gripped the public—and sometimes the scientific—imagination. Filled with comprehensive drawings, classifications, and maps, their book offers an invaluable and unusual resource for the intrepidly curious to investigate these sightings firsthand or to simply enjoy the fascinating accounts that others have given.