Andrew Garfield was considered for the role but Tobey Maguire was cast. Though he filmed his scenes, Maguire was later replaced by Rafe Spall because the director thought that Maguire was too famous for such a small role and it would have been distracting.
As in the novel, the name of the Japanese ship is Tsimtsum. Tsimtsum is in fact a Hebrew word used by the 16th-century Kabbalist Isaac Luria to denote God's "contraction" of Himself from the world at Creation. In the novel, the adult Pi mentions doing a college thesis on Luria's theories about creation. In the movie, he simply mentions teaching a course on Kabbalah and does not specifically reference Luria.
Piscine Molitor Patel (Pi) was named after a swimming pool (Piscine Molitor) in France. It is next to the park Bois de Boulogne, and between Stade Roland Garros and Parc des Princes. The pool was classified as a French monument historique on March 27, 1990, after having fallen into disuse and closing in 1989.
Yann Martel, the author of the book has stated that his inspiration for the book's premise came from reading a book review of Brazilian author Moacyr Scliar's 1981 novella Max and the Cats, about a Jewish-German refugee who crossed the Atlantic Ocean while sharing his boat with a jaguar.
Pi, played by Suraj Sharma, was never actually in the boat with a live tiger. Most of the tiger was very high-tech CGI technology and only some scenes like the tiger swimming in the water had a real tiger used.
Newcomer Suraj Sharma, who plays the main character Pi, never intended to audition but was cast accompanying his brother to the casting call. He was ultimately chosen by Ang Lee's team among more than 3,000 hopefuls for the lead role.
While Pi (Adult) and the writer are talking seated in front of the Montreal Harbor, a ship called Mignonette is visible in the harbor. Mignonette is the name of the yacht involved in the events of R v Dudley and Stephens, from which Yann Martel got the name of Richard Parker.
The carnivorous island has the shape of a lying Vishnu (a Hindu deity), and can be seen in a long shot of the island.
Throughout the movie, there are shots which feature the profile view of a supine Vishnu (the sleeping Hindu God seen in the barge). He appears in the distant hills when Pi is on holiday and visits the church to drink the holy water. He appears in clouds on a dark night at sea. He is in the shape of the Marinas Trench on the oceanic map. He is also the carnivorous island in profile.
Spoilers: The items below may give away important points in the story
The name Richard Parker is subject of a strange synchronicity: in the Edgar Allan Poe's novel book "The Narrative of Arthur Gordon Pym of Nantucket", published in 1838, Parker was a sailor who survived the sinking of his ship together with three others, but was cannibalized by the other three survivors in order to survive. In 1884, a ship called Mignorette sank in the ocean, in which four people survived, including a cabin boy named Richard Parker, who was subsequently killed and eaten by the other three survivors. Yann Martel, writer of Life of Pi's novel book, named the Bengal tiger as "Richard Parker" based on these events.
Towards the end of the story, Pi mentions that the carnivorous island was never seen again, and it creates an element of doubt about the version of the story with the tiger. In the beginning of the movie, when Pi tells the writer about Lord Vishnu, he says, "Vishnu sleeps on the shore-less cosmic ocean, and we are the stuff of his dreams." The carnivorous island had the shape of Vishnu lying on the ocean.