Sir David Attenborough explores the surprisingly vibrant seas that surround the British Isles. The vast watery wilderness around us is over three times the size of our land mass, and yet to many, our oceans remain a mystery. Full of colour and teeming with life, the seas of Britain and Ireland are crucially important to a range of wildlife. This episode goes beneath the waves to uncover the thriving habitats that exist along our 22,000-mile coastline.
In winter, clear evidence of the ocean’s abundance can be seen on a beach in Norfolk. Thousands of grey seals congregate on the shoreline to give birth. Britain and Ireland are home to 40 per cent of the world’s grey seals, and the number being born on our shore rises every year. Once the newly born pups are weaned, the females are ready to breed again, and heavyweight males enter violent, bloody fights to win a stretch of beach, and the females along with it.
Beyond the beach, the vibrant shallows contain several important habitats. Rich beds of seagrass are nurseries for a range of animals, while also acting as very important carbon storage areas. They are also home to one of the strangest fish in our waters, the seahorse. We follow a male and female as they perform a balletic mating dance in the water, delicately entwining their tails. The stakes are high, as these animals mate for life.
In a touching piece to camera, Sir David bids a fledging Manx shearwater chick farewell as it embarks on a 6,000-mile journey across the oceans to South America. There is no better example of how important the British Isles and its abundant seas are to the survival of wildlife worldwide.

In every ocean… just beyond our shores…lives an animal with characteristics we think of as ‘human’ – intelligent, social, curious, gentle, and fierce. They build cities, use tools, and collaborate with other species to hunt. They have personalities – some are bold, while others shy. These animals can change their skin colour, texture, and body shape in a blink of an eye and see in wavelengths beyond our vision. Recent studies reveal octopuses’ consciousness, sophisticated decision-making, and unique personalities. On tropical reefs, in frigid waters, from the shoreline to the deep sea and everywhere in between, the octopus have made a home. Join us as we reveal ‘Secrets of the Octopus’.
In the first chapter, whether transforming their body shape and color to disappear or mimicking their deadliest enemy, Octopus use shape-shifting superpowers to survive.

In the captivating second part of “Our Universe”, chapters 4 to 6 are presented together in an unmissable journey through the cosmos and life on Earth. These episodes delve deep into the elements that formed our world, the essential role of water, and the unseen forces that shape our lives. They offer an enthralling exploration of our place in the Universe. Dive in to experience this profound story of existence, from stardust to soulmates.
In the fourth chapter, we uncover how the elements essential to life were forged in the hearts of stars. Following a green sea turtle’s quest across the ocean for these elements, this episode reminds us that life is built from the remnants of ancient stars. The fifth chapter takes us back to the miraculous arrival of water on Earth, exploring how this vital substance transformed a barren landscape into a thriving blue planet. In the final chapter we witness gravity’s grand influence on life, following two king penguins as their journey of attraction and survival unfolds against the cosmic force that binds us all.