National Geographic's Dr. John Francis and Crittercam series host Dr. Mike Heithaus join biologist John Calambokidis on an extraordinary expedition to answer questions about the largest animal on the planet: the blue whale. At home in the oceans of the world, blue whales are wide-ranging and elusive - and therefore very challenging to study. With hydrophones, Crittercam and a research vessel that's little more than a rubber raft, John C., John F., and Mike strike out for the open ocean, hoping for a close encounter with the largest, loudest and possibly most mysterious creature in the sea.
