Akshay Kumar was ready to opt out of the film if he had to mouth anti-Pakistani lines - he didn't want to hurt the feelings of his Pakistani fans. He rejoined the cast when his lines were rewritten.
Akshay Kumar asked director Anil Sharma to give a disabled fan of his a role in the movie. The fan, Puran Chauhan, who lost his leg in a roadside accident at the age of five, was given a small part.
The name of the movie is based on the famous Indian patriotic song "Kar chale hum fida jaan-o-tan saathiyon. Ab tumhare hawale watan sathiyon" from the movie Haqeeqat (1964). The movie also has a title track based on the same song. The lines "Kar chale hum fida jaan-o-tan saathiyon. Ab tumhare hawale watan sathiyon" mean "We are sacrificing our lives and bodies, friends. Now the country is in your hands, friends".
Five ships were used for the starting scene and sailed from Vishakapatnam, with shooting happening as far as 200 km from land. Quite a few of the crew were noted to have gotten sea sick.
The scene where sea water gushes into the ship after being torpedoed, was shot inside the Indian Navy's "Damage Control Simulator" at the land base INS Shivaji.