IT was a terrifying natural disaster that swept away entire communities and left an estimated 280,000 people dead and more than one million homeless.

Now the Indian Ocean tsunami of Boxing Day 2004 is being recreated for a new blockbuster film, The Impossible – with a Scottish firm using its expertise in creating tidal waves for some of the most dramatic scenes.

Edinburgh Designs has revealed how it recreated the giant wave with stunning authenticity for the film starring Ewan McGregor and Naomi Watts, which is based on a real-life family's survival in the aftermath of the disaster.

Despite employing only 10 staff and being more used to testing the sea-worthiness of oil platforms and harbours, or building wave pools for holidaymakers at water parks, the company was hired to recreate the moment the tsunami tidal wave crashes down on a beachside holiday complex in Thailand.

Douglas Rogers, a director of Edinburgh Designs, said: "They wanted the dramatic first shot of the wave to look convincing and avoid the familiar CGI look of most blockbuster films.

"Most of our customers are looking for accurate, perfect waves. For The Impossible project, director Juan Antonio Beyona was looking for the opposite effect. His vision was a mean, ugly and chaotic wave; something that looked more evil than one dreamed up by the effects guys.

"We had to go right back to first principles and unlearn everything we knew about making precise waves to create something really messy"

A massive pool was built at the Ciudad de la Luz film studio near Alicante, Spain, while the scale model of the resort was assembled in Germany.

The wave machine took months to build and the Scots team was in constant contact with the film crew, sending them footage of its progress until the desired effect was achieved.

Brown dye and debris were added to the water to make it look authentic, and then it was time to turn the machine on.

But Mr Rogers and colleague Matthew Rea said he still had his fingers crossed, as the effect shot was so complex there would only be one chance to get it right.

Mr Rea said: "The final day of the shoot was incredibly tense. There would only be one take then the model would be destroyed. We felt a burden of responsibility as technical failure would be an embarrassment to us and financial disaster for the producers.

"After hours of last minute attention to detail we were ready to go. A torrent of a thousand tons of water with the power of eight F1 racing cars smashed through the model.

"The water towered like a wall above the model then smashed though the bungalows. One torrent rose like a menacing fist ready to hammer the buildings. The crowd burst into applause; it had all worked to perfection."

Watts has revealed she battled bronchitis and stomach problems after swallowing large amount of water during filming. She said: "Physically [it was] the most demanding thing I've ever done. Working with water is always going to be tough. It was five or six weeks in those tanks."

l The Impossible is released across the UK on January 1.