The last two-thirds of Yann Martel's novel The Life of Pi center around the theme of Pi's survival on the Pacific Ocean. At the beginning of the novel, Pi's family sells their zoo in India and embarks for Canada on a Japanese cargo ship. Many of the animals from the zoo are on the ship because American zoos will pay a higher price for them.
When an explosion causes the ship to sink, Pi ends up in a lifeboat with an orangutan, a zebra, a hyena, and a Bengal tiger named Richard Parker. Richard Parker is the only animal to survive the ordeal with Pi. He is at sea for 227 days. In that time, he survives two predators (the hyena and the tiger), storms at sea, exposure to harsh sun, cold temperatures, and salt spray wounds. He survives extreme hunger and thirst before he figures out how to hunt and get to the supplies on the lifeboat. Here is what Pi says about his thirst after three days at sea:
With a tiger aboard, my life was over. That being settled, why not do something about my parched throat? I believe it was this that saved my life that morning, that I was quite literally dying of thirst. Now that the word had popped into my head I couldn't think of anything else, as if the word itself were salty and the more I thought of it, the worse the effect. I have heard that the hunger for air exceeds as a compelling sensation the thirst for water. Only for a few minutes, I say. After a few minutes you die and the discomfort of asphyxiation goes away. Whereas thirst is a drawn-out affair.
Pi also survives a carnivorous island, an encounter with another stranded person at sea who tries to kill him, and the extreme fear and loneliness of his situation.