With its giant mountain ranges, vast deserts and deep canyons, America’s Wild West is full of dramatic landscapes. But what of its shoreline? In the last of this classy trio of documentaries, we explore the mysterious Sea of Cortez, between mainland Mexico and Baja California.

Ocean giants including 200-tonne blue whales are attracted to its warm waters, while sea lions cavort, undersea forests of kelp grow at record speeds and grunion fish spawn at the full moon (providing peckish pelicans with a tasty treat).

James Norton’s gentle narration only adds to our enjoyment…