What is the atmosphere like throughout the story?

When discussing the atmosphere of a story, this usually refers to the mood. The mood is determined by how the audience or reader feels while experiencing the story through descriptions of language, evolution of the plot, and character development. Through Martel's Life of Pi, the atmosphere changes depending on Pi's life experiences. For example, the first part of the story is about the lessons Pi learns as a boy growing up in the Zoo. It also presents Pi's character as one having intellectual talent as well as deep spiritual convictions. During this first part of the book, Pi is relatively safe as he learns and grows from boyhood to adolescence.
However, the second part of the book takes this young teen from his safety zone and throws him into the chaos of a shipwreck and surviving at sea for months! It is at this point that tension arises for Pi as well as for the reader. The atmosphere shifts from one of relative safety to one of dire concern for Pi's life as he manages his survival on a lifeboat with wild animals and an endless ocean. Readers' emotions might run the gamut as the atmosphere of the story changes from one chaotic trial to another while Pi strives to survive. Then, when Pi achieves success by training the tiger or feeding himself one more day, the mood changes from tension to relief. In the end, Pi finds his way safely off of the ocean; but of course, this is understood from the beginning, since the reporter tells the story from Pi's home in Canada. Either way, the story is amazing and brings with it shifting moods: fear and peace, tension and relief, despair and victory.
Then, during the third part—the ending, when the Japanese men ask for Pi's story—the atmosphere becomes one of confusion because the reader doesn't know which story to believe. In the end, Pi asks the big question as follows:

"So tell me, since it makes no factual difference to you and you can't prove the question either way, which story do you prefer? Which is the better story, the story with the animals or the story without animals?" (317).

Some readers may feel disappointed with the ending because the animal story is more entertaining and inspiring, but Pi leaves it to be decided on an individual basis.