National Geographic marine biologist and explorer Manu San Félix has dedicated more than 30 years of his life to studying and fighting for the conservation of the Mediterranean. Much of this experience is reflected in this documentary, in which San Félix leaves the island of Formentera, where he lives, to embark on a journey around the waters of the Spanish Mediterranean, in order to show how human action has turned one of the planet’s richest marine enclaves into one of the most under threat.