Black Sea: behind the scenes of Jude Law's submarine thriller shot in Crimea...and Kent

“A submarine is exactly the same as a spaceship. It’s taking you as a human being into a place you shouldn’t be, and it enables you to live. But, if something goes wrong with that machine, or the people who are operating it, you’re doomed.”

Originally planned as a TV movie for Channel 4, Black Sea snowballed into a bigger production and needed more funding and a movie star. Macdonald was adamant about having a British lead, to suit Utopia-writer Dennis Kelly’s script.

“Jude [Law] got hold of the script and wanted to talk about it," he explains. "I thought Jude Law wasn’t right for this character but I’d never met him. I went to see him and I was so impressed with his understanding of the script and his desire to transform himself. I’d seen him in the theatre playing an Irish sailor before, in a Eugene O'Neill play called Anna Christie, he got rave reviews, and I thought he could access this rough-man-of-the-sea thing.”

Spend a weekend in Kent with RT Travel, and step inside a real submarine, see here for accommodation

Jude Law bulked up to play gruff Scottish Captain Robinson in the movie. “He does pull it off and he shows that he’s a great actor,” says Macdonald, who tasked Law with living on a submarine for four days and four nights before he started filming.

“Jude went on a nuclear sub with the Navy to Gibraltar, with 18 smelly men. He really immersed himself in it,” explains Macdonald. “He was the butt of a lot of jokes on board, they called him a ‘softy southern actor,’ but I think he got on well with them. He said the hardest thing was that he was six ours on and six hours off, so you never really get much sleep.”

For the director, much of the inspiration for the movie came from actually being on a real-life submarine. “We found out about this sub in Kent [in the River Medway]. The fact that it was a 1960s Russian sub really got Dennis [Kelly]'s imagination going. We came up with this idea that half the crew would have to be Russian as they would know how to operate this thing. We contacted the owners [of the vessel], we went to visit it, and we started writing around this sub.”

The Black Widow sub used for filming is not open to the public as it’s privately owned, but it can be seen from the river’s edge, and visitors can step inside a real sub at the nearby Chatham Dockyard. Experiencing a real submarine made all the difference to the movie, explains Macdonald. “It really helped, because everyone had to really learn what it was like being in a big metal tube,” he says, “The whole point of this movie is to feel claustrophobic and realistic.”

Macdonald also planned to shoot a chunk of the movie in Crimea, where Captain Robinson (Jude Law's character) buys the vintage submarine he needs to go his pirate-esque mission to recover lost gold in the bowels of the ocean.

“We were originally going to shoot on a Ukrainian submarine, which was still operational,” explains Macdonald. “It was still working and was the same vintage as the submarine in the film, which is incredible as it was built in '62 or ’63.”

On a recce to test a new camera, Macdonald and a cameraman captured a few shots. The plan was to return for the main shoot with the actors and rest of the crew, “but Universal wouldn’t let us go because of insurance issues,” explained Macdonald – “they obviously had a hotline to the Ukraine.” In February 2014, Russia invaded Crimea and it was later annexed by Putin. Luckily, Macdonald had enough Crimea footage to go ahead with the film.

“It’s a period piece already! Crimea is now part of Russia,” says Macdonald, who hopes this can only help with the tension of the movie. “Now people now know what a bunch of guys borrowing a submarine from Sevastopol Port represents. Them going underneath a Russian fleet takes on a certain peccancy.”

Black Sea is out now in UK cinemas

Spend a weekend in Kent with RT Travel, and step inside a real submarine, see here for accommodation