What time is Blue Planet II on BBC One tonight? The groundbreaking nature documentary narrated by David ...

BLUE Planet was the astonishing and groundbreaking nature documentary which took us under the sea in a whole new way.

And 20 years on, the BBC series is back, after film crews spent four years scouring the seas for a fresh cast of mysterious and beautiful aquatic creatures. Here's when to watch...

A brand new series of Blue Planet is back on BBC One

When is Blue Planet II on BBC One?

The new series of Blue Planet II continues with episode two TONIGHT, Sunday, November 5 at 8pm.

The seven-part documentary sequel comes 20 years after the original series, which set out to explore the deepest and darkest realms of the world's oceans.

One of the most memorable and heartbreaking scenes was a brutal attack by a group of killer whales on one of their babies.

Other creatures featured included dolphins, fish including marlins and sea birds.

And when it aired in 2001, it received widespread acclaim from both the public and critics alike.

It also made nearly £20 million in the sales of DVDs, books and broadcast rights, while the show was sold to more than 150 territories across the globe.

Creatures of all shapes and sizes will be introduced to viewers

Is there a trailer for Blue Planet II?

Yes - a brand new trailer for the series dropped on October 20.

It gives fans a tantalising peek at what's in store, announcing that "new science and technology" will allow us an even closer look under the waves in the new episodes.

Dozens of creatures, from whales to seahorses, are seen in the eye-popping promo clip.

Latest trailer for Blue Planet II gives glimpse of epic new series narrated by David Attenborough

Is David Attenborough involved?

Renowned naturalist Sir David Attenborough will be presenting the series and his familiar voice will form part of the narration.

Sir David turned 90 last year and had been rumoured to have been on the verge of retirement.

But his involvement in Blue Planet II is being seen as a coup for the BBC.

Despite celebrating his 90th birthday last year, Sir David Attenborough will once again be presenting the series

Sir David said: "I am truly thrilled to be joining this new exploration of the underwater worlds which cover most of our planet, yet are still its least known."

Last year, he was the voice of the successful Planet Earth II series, which regularly drew in more than 10 million viewers.

And it is believed Sir David's reputation will help the BBC with international sales of the new programme.

What new sea creatures are there?

Blue Planet II is set to feature even more aquatic animals and has used highly ambitious filming techniques to capture them in their natural environment.

Some never before seen animals have been caught on film for the first time - including the Hoff Crab, which is named after Baywatch star, David Hasselhoff.

Among the creatures to be filmed for the first time and featured in the series include hairy-chested Hoff crabs, snub fin dolphins that spit water through the air and a tool-using tusk fish.

Other animals set to be shown also include coral groupers, reef octopus and giant trevally fish.

All kinds of sea life will be looked at in close detail

New specially developed camera technology allowed the crew to film predators front-on, and even "travel" on the backs of whales, sharks and orcas.

One scene will even show a sperm whale mother and her young calf as they head deep into the abyss to hunt.

Where was it filmed?

Camera crews travelled to every continent and worked across every ocean to film scenes for the new documentary.

The series is set to show both icy polar seas, vibrant coral atolls and the storm beaten Atlantic coastline.

Blue Planet II is set to feature even more aquatic animals and has used highly ambitious filming techniques to capture them in their natural environment

Viewers will also be shown new landscapes such as methane volcanoes which erupt in the Gulf of Mexico and the so-called boiling sea phenomenon in the Pacific Ocean.

For the first time, the show will also show footage of the Antarctic at 1000 metres deep after taking two manned submersibles to explore the polar ice cap.

Executive Producer James Honeyborne said: "The oceans are the most exciting place to be right now, because new scientific discoveries have given us a new perspective of life beneath the waves.

"It will provide a timely reminder that this is a critical moment for the health of the world's oceans."

Giant fish leaps out of the water to eat a bird in teaser for first episode of David Attenborough's much anticipated Blue Planet II