Aamir, 47, who did not know swimming at all, also learned underwater swimming, which is more difficult than the regular one, for his character of Inspector Surjan Singh Shekhawat.
"Actually Dave (trainer) is helping me prepare under water sequence, he is helping me with breathing exercises which increases my lung power and allows me to stay under water for longer," Aamir had said.
Director Reema Kagti was impressed with Aamir's diving skill while shooting the movie. The water scenes have been shot in London.
Also starring Kareena Kapoor and Rani Mukherji, the film hits theatres this Friday.
