Courtesy of a scratchy phone line, JC Chandor's question 'Am I speaking to Scotland?" sounds like he is calling ship to shore from the middle of a stormy Atlantic rather than London to Glasgow.

It is a fitting start to a conversation about the American director's new film, All Is Lost, the tale of one man and the sea.

Not just any man, mind you. The star of Jeffrey C Chandor's drama, which has no dialogue, no scenes on dry land, and no name for its solo character, is Robert Redford. The 77-year-old Oscar winner plays a man of a certain age sailing his 39ft yacht through the Indian Ocean when it is involved in a calamitous collision with a shipping container. Adrift and alone, the odds on his survival are diminishing by the hour.

Chandor, who was Oscar-nominated for his first feature, Margin Call, a 2011 drama about the financial crash, had the idea for a film set at sea while travelling by train from his home in Rhode Island to work in New York.

He and his wife, an artist, had recently had their second child. Margin Call, his first longed for feature film after a long career in commercials and documentaries, was just being edited. As Chandor looked out the window at the little coastal towns speeding by, their boats in dry dock for the winter, he began to muse about "The Letter", the kind of missive he would write home if he was lost at sea, full of regrets and longing for things not said and done.

"At that point I had put my entire life on hold, I was not making any money off Margin Call and I didn't know what Margin Call was going to be. So it was a very exciting time in my life but also stressful."

The letter eventually led to Chandor writing 15 to 20 pages of what eventually became a 31-page script. A week later, he took Margin Call to Sundance, Redford's film festival. Caught up with promoting Margin Call, he was not thinking of Redford for All Is Lost until he heard him speak at a meeting - "this loud, beautiful rumble" - and something clicked. He sent Redford the script, and a week later the call came. "The next thing I know I am flying to Los Angeles."

Bizarrely, Redford had been surprised to receive the script. "There's something kind of ironic in that, all these years after starting Sundance and starting the film festival, none of the filmmakers that I supported ever hired me," he jokes. "They never offered me a part - until JC."

Back to LA, where Chandor had a whole presentation prepared for Redford. Six minutes into the meeting Redford looked at him and said, "Look, don't worry, stop talking. Let's do this. I just wanted to make sure you had thought this through and that you weren't crazy, but I love it."

Crazy is the usual diagnosis for any director who wants to set a film on water, and so it sometimes seemed on All Is Lost. Besides filming in the Pacific and the Caribbean, the team went to the famous Baja Studios in Mexico, built for James Cameron's Titanic.

"We did pretty much everything that you can do to a boat on film," says Chandor. "We sunk it, brought it back to life, sailed it, then put it through a massive storm, flipped it over, and sunk it again."

Chandor's parents were weekend sailors and he and his sister went out occasionally when they were younger. In his twenties he did an open ocean sail out of curiosity, and lived to rue the day.

"I always wondered why people did that and now I will never ever go back. We got caught in a nasty storm, nothing like in the film, but I had experienced that feeling and the noises. I am not one of these people who is a daredevil or anything. But that was the first time I had ever felt that small."

Redford, who did most of his own stunts, including climbing the 65ft mast, certainly earned his small pay cheque. It was physically and emotionally exhausting for everyone, says Chandor, but especially Redford.

"It was more the mental side. It was certainly physically tough, a lot of the stunts he does were really intense. The far more difficult thing for both of us was the idea every morning that you woke up you knew you were going to be wet all day."

Just as mentally draining was making a film with no dialogue. Margin Call, featuring a team of stressed out financiers played by a cast including Kevin Spacey, Jeremy Irons and Stanley Tucci, had been a high-octane jabberfest. In All Is Lost, Redford barely says a word. "I totally underestimated the loneliness of not speaking," recalls Chandor.

As with Margin Call, the punt of going for a highly original, low-budget, character driven film appears to be paying off for Chandor. Redford has been nominated for a Golden Globe for his performance, and there is Oscar chatter besides.

Redford, for one, is impressed by the 40-year-old. "The thing that is incredible is how busy his mind is. It's a quicksilver mind, and I find it really fascinating."

For Chandor, all is just beginning.

All Is Lost opens on Boxing Day