On a trip to Hawaii, Jonathan meets the critically endangered Hawaiian Monk Seal, then he travels to Bonaire to dive with a group of wounded veterans learning to dive. Finally, he participates in a fish census in Massachusetts.
Jonathan joins a team of underwater archaeologists on a project to excavate the remains of Blackbeard the Pirate's ship. Then he travels to Hawaii to meet Manta rays that feed in divers’ lights at night.
Jonathan travels from the St. Lawrence river to the Caribbean, looking at invasive species and their effect on the environment. Then he explores 1000 feet down in a special submarine and meets an astonishing variety of deep sea animals.