The woman next to me is excitedly taking pictures on her iPhone and dashing from starboard to port to get the best view of the action: which would be normal behaviour were it not for the fact she’s Inka Cresswell, one of the team who’s spent six years making the five-part natural history film, Our Oceans.

“Is this not a bit of a busman’s holiday for you?” I ask. “It’s actually really nice,” she laughs. “I never get bored with the ocean. I even wanted to go scuba diving on my honeymoon but we agreed that might be a step too far.”

I’ve been invited to join executive producer James Honeyborne, series producer Jonathan Smith and researcher Cresswell to understand what it took to make the epic new Netflix series.

The team spent more than 53,000 hours in the field across 33 countries, including 500 days living at sea and 4,000 hours diving underwater. The resulting series is narrated by former US President Barack Obama and has spawned 20 new scientific papers from its discoveries.

And yet here they are, excited about a five-hour boat ride run by a company that usually runs whale-watching trips for tourists. We have been exceedingly lucky, seeing pods of orcas teaching their young to hunt a sea lion, and hundreds of sea lions feeding on a giant bait ball of anchovy alongside eight humpback whales.

Smith says, “These moments excite us as much as anybody. If we can bring that excitement, magic and wonder to the screen, then we can protect our oceans.”

Key to Our Oceans was not just telling ground-breaking stories but finding a connection to sea-life. The team wanted to show those who grew up fearing the ocean after watching Jaws that life under the waves is full of stories that are completely relatable. Jonathan Smith explains: “The species living under or beside the water are sharing the same challenges and joys of life that we all are. It’s only by starting to understand this world that you realise, ‘This isn’t something to be scared of. This is something to be in love with.’”

Honeyborne, who was director and executive producer on the BBC1 series Blue Planet II, adds, “We’re trying to change the perception of fish and cetaceans being cold and slimy and alien-looking. Sometimes we find ourselves looking at a fish thinking, ‘You’re a lot more clever than we thought’. We see parents fussing over their kids, we see love stories emerging. That’s the joy of it.”

The team spent six months researching stories to film: but some of the most fascinating were completely unplanned, as Smith explains. “We script stories, but nature doesn’t read the script. That can make life tricky but it can also throw wonderful surprises our way.” His favourite example of this is the tiny veined octopus in the Indian Ocean that hides among debris on the sea bed in order to hunt.

We see parents fussing over kids and love stories emerging

First, they filmed the octopus embedding itself in a see-through plastic cup before she cleverly realised that if she could see out, her predators could see in – so she changed tactic and found two halves of a clam shell as the perfect hiding place from which to hunt for crab.

And when passing fish smelt the clam remains and started loitering, the octopus used her siphon to pick up stones to fire them at the fish.

Smith says, “The story took a really crazy turn at that point. She picked up this stone, shot the fish in the head, and basically turned herself into a gun! It was magical and showed how clever she is. There’s a scientific paper being written about it now. It’s what we try to do with every story, to take you on a journey with twists and turns to rival the best Hollywood scripts.”

Because the octopus is so tiny – about six inches – and the action happened so quickly, the team didn’t realise what they had filmed until they got out of their wetsuits and into their hotel rooms to look at the footage. “What they saw,” says Honeyborne, “was a fish swimming up towards the octopus and then being startled, like it had been slapped in the face. It was only when we went through it in slow motion, frame by frame, that we saw this pebble. That was the ‘penny drop’ moment. We then spent another 100 hours filming it.”

Other highlights included filming the narwhal – an Arctic creature known as the “sea unicorn” – using its tusk with immense dexterity to separate and stun fish. “It’s one of those amazing near-mythical animals that we don’t know much about,” says Honeyborne, “so to see it doing something so astonishing was a great moment.”

The crew were able to film this behaviour in part by using a drone camera that could track the shy narwhal from the sky. New kit also allowed them to film species such as brightly coloured starfish that live as deep as 3,000 metres in dark and freezing conditions.

But as well as the joyous new findings, there is also a focus on the environmental impact of humans on our oceans, epitomised in a heartbreaking scene where a polar bear cub isn’t able to keep up with its mum and sibling; almost half of polar bear cubs don’t make it to their first birthday due to thinning ice caps. Weak with exhaustion, the mum has to help it climb the ice. Another heart-stopping moment comes when the cub starts playing with a piece of discarded rope on a beach and becomes entangled.

Cinematographer Alex Vail says, “You could see in this cub’s face that it was really scared. The rope did slip off, but it was a scary moment.”

After Blue Planet II sparked international campaigns over single-use plastic, Honeyborne hopes Our Oceans will have a similar effect. “We saw that after [Blue Planet II], people felt emotionally closer to life beneath the waves. They cleaned beaches and started using less plastic, and that’s the warmth of the human response. If watching this means you come to love life beneath the waves, and that leads you to take action, that would be wonderful.”