Christopher Nolan's next epic, The Odyssey, follows the journey of a Greek warrior trying to make his way home across the ocean after the Trojan War – so, naturally, it involves a lot of sailing.
However, as you might expect from a film of this scale, nothing was done by halves, meaning the cast had to actually learn to sail for real.
"When I was writing the script, every time I’d write something on a boat, I thought, 'Ugh, do we have to be on boats?' Because I know what it takes to film on the open water," Nolan told The Independent. "They're like, 'Well, it's The Odyssey, so yes.' Having an ancient vessel, and a boat built according to those ancient specifications – where everything's wooden – and being out on the open water with the cast and crew, it was a tall order."
This involved assistance from "the best in the business" marine coordinator Neil Andrews, whom Nolan also worked with on Dunkirk, as the cast "bedded in with the crew of the ship we were using."
"These guys – Odysseus' crew – learned how to row the thing," Nolan added. "They learned how to raise the yard, raise the sails. And so by the time we got there with our camera, you know, Hoyte [van Hoytema, cinematographer] and I are on our own deck. We were shooting it kind of like a documentary. It was really thrilling to do. But boy, it was tough. It was tough on everybody."
Though the film still hasn't been released, it has been subject to plenty of criticism online already. But, Nolan has already shared that he's not bothered by it.
"Comes with the territory," the director has said. "But look," he added, "these conversations that happen before people see the film – they're always irrelevant, because no one having them knows what the film actually is yet."
The Odyssey is in theaters this July 17. It's an adaptation of Homer's epic poem of the same name, and you can find out everything you need to know about the source material in our The Odyssey beginner's guide.
For even more, check out our current ranking of the best Christopher Nolan movies, or our roundup of the most exciting upcoming movies.