Gerard Butler's submarine prep
Gerard Butler spent three days on a submarine to prepare for his role in 'Hunter Killer'.
The 48-year-old actor and the movie's director Donovan Marsh decided to experience life on a submarine to prepare for the film, which follows the story of submarine Captain Joe Glass, who is looking for a US submarine in distress in the Arctic Ocean.
Marsh said: "Gerry and I were actually able to re-enact scenes from the film in the sub with a real Naval crew. That was so invaluable for both of us. When we were back on dry land and on set, we were able to bring all that intense realness we experienced to the execution ... You realise when you are on a submarine ... everything starts leaning and everything that isn't nailed down just goes flying. It was quite a thrilling feeling to experience and I wanted the actors to be able to have that as much as you possibly can on dry land ... It's traditionally been done by tilting the camera but that just wasn't real enough. Mounting the set on a gimbal wasn't easy but everyone loved it. It created a very spontaneous tension and gave everyone the feeling of being at sea."
Meanwhile, Gerard previously revealed he loves it when an action film just "works".
He shared: "We always try our best but sometimes you make a movie and you go, 'OK, that really didn't work'. But, when it works, honestly, there is nothing better. There is nothing better than walking into a room and feeling the excitement of somebody who has watched a 300 or a Hunter Killer. Because there are always high stakes and there are always big ideas. You make these movies with original content, original ideas - not some intellectual property - and you're therefore dangling a little more, you know? You could fall on your a**. So, therefore, when it works, it's so exciting because of those high stakes. When they work they are incredibly exciting, thrilling, fun."