The new drama chronicles the story of a family's survival in the aftermath of the horrific Indian Ocean tidal wave that killed more than 230,000 people on 26 December, 2004.
McGregor travelled to Thailand to shoot scenes on location and admits bouts of bad weather prompted fears among locals that the project was doomed.
He tells Britain's The Guardian newspaper, ""It was a very difficult film to make, especially with the weather. We had a lot of rain, and the actual day of the original tsunami was very beautiful, so we had to wait. There was some talk among the Thai crew that the film might be... cursed, you know? That the spirits or the gods might be preventing us from making the film. There were some spooky moments.""
The actor tells the publication the crew sent lanterns into the sky to ""appease"" the spirits.