On the final day of filming, after five weeks of following a single dolphin around a hunting ground the size of Manhattan, she popped up near the crew’s boat to offer them a ‘little goodbye’. The BBC Natural History production team had assumed they would never see her again. Yolly Bosiger, the filmmaker and director leading this episode, titled Tropical Seas, was, by her own admission, “properly crying”.

“You do get quite close to these animals,” she tells Oceanographic. “And I just really hoped she’d be okay.” That innate human empathy and connection is at the core of Blue Planet III. It arrives 25 years after the very first series, the seminal piece of work that brought the magic of the ocean into living rooms worldwide. “We knew we had to pick up that baton,” says executive producer Elizabeth White, “and to continue to tell the story of what is taking place in our Blue Planet.”

There is plenty here of what we know and love of the Blue Planet legacy: an epic score, this time by Hans Zimmer and Bleeding Fingers Music, accompanies scenes of triumph, tragedy, love and blunders; Attenborough’s warm narration brings characters to life across the polar regions, our tropical and seasonal seas, the open ocean and its deepest depths; and a final episode looks ahead at action already being taken to protect our seas, whether that’s tracking marine mammals to coordinate protection, studying the impacts of forever chemicals, or tackling the plastic crisis nearly ten years on from the profound legacy of Blue Planet II.

The world in which Blue Planet III lands has moved on significantly from that of its predecessors. Twenty- five years on from its first iteration, and audiences are far more informed of the life that lies in the ocean beyond our shorelines. And among younger audiences, there’s growing awareness of what’s at stake. Today, the Carbon Literacy Project tells us that 62% of young people experience anxiety, anger or helplessness about the climate crisis, yet polarisation is at its peak. Political leaders like Donald Trump and Javier Milei openly express climate scepticism, despite 89% of people wanting stronger political action on the environmental crisis according to the Covering Climate Now initiative.

The media landscape has fractured too. Attention is harder than ever to command, terrestrial television is in decline, streaming and YouTube are on the rise, and DVDs are largely considered a novelty of the past. No, this is not the same audience that once sat at the television to watch the original. Blue Planet III’s production team were faced with the defining challenge of our time: how to cut through the noise.

It was clear that the lodestar for the series was connection: bringing the audience into our ocean in a way they had never been brought before. That meant building colourful characters, drawing on technological developments, and using the wealth of scientific and local knowledge developed over the last quarter of a century.

“We wanted to show our audience that the ocean is not full of slippery, scaly things. It’s full of really amazing animals, and we wanted people to really relate to them,”Elizabeth tells us.

Part of building that connection is understanding the challenges facing each animal, showcasing what makes them tick and what drives them to act as they do. “That makes it much easier to see parallels with our own lives,” Elizabeth explains. That might be a huddle of penguins shuffling along, reminding a viewer of their commute; an intrinsic bond with a creature giving birth in the ocean’s deepest depths; or the humour of some of its most charming creatures.