Movie is based on the life of Belon, who was in Thailand with her two sons and husband when the disaster hit the Indian Ocean in 2004. Watts, 44, plays the lead character in the film.
The actress dressed in white, happily posed with Belon who allowed the filmmakers to bring her struggle on screen, reports dailymail.co.uk. The movie centers around Watts character trying to search for her husband who goes missing post the disaster.
The movie also stars Evan McGragor and Tom Holland. Directed by Juan Antonio Bayona, the film is slated to release Dec 21.
Photos: Akshay Kumar, Taapsee Pannu promote 'Naam Shabana'
Flashback: When sexy models sizzled in bikinis at Tokyo fashion show
Photos: These Indian cities top the list in online purchase of sex products
In pictures: Indian-origin artistes in Hollywood
Photos: Varun Dhawan and Alia Bhatt at studio in Bandra