Neil deGrasse Tyson interviews legendary oceanographer Sylvia Earle, aquanaut Fabien Cousteau, and actor Adrian Grenier and discusses Earth's oceans with comedic actor Scott Adsit and ocean conservationist Laure Katz.

Neil deGrasse Tyson features his interview with master navigator and traditional Polynesian voyager Nainoa Thompson and discusses the science of celestial navigation with comedian Maeve Higgins and navigation instructor Frank Reed. Author Dava Sobel discusses the "longitude problem" from her best-selling book, Longitude.