Boiling seas, huge flying fish which snatch birds from the sky and armour-clad octopuses were once thought to be purely the stuff of fisherman’s tales.

But remarkable new footage, captured over four years by BBC filmmakers for Blue Planet II, has proven that many sailors’ myths are actually true.

Sixteen years after the original The Blue Planet aired, the series returns this month, promising a raft of new scientific discoveries and filming firsts, which reveal the surprising intelligence and complex social lives of creatures beneath the waves.

Among the most astonishing discoveries was made in the Seychelles where filmmakers found that predatory Giant Trevally fish leap into the air, to grab sooty terns on the wing.

“A fish that launches itself, missile-like, to take birds from the air, sounded too extraordinary to be true,” said Miles Barton, Producer for the Coast episode.