In the novel, water is so common, so expected, we forget it was there altogether. At sea, there is a boat, a lion and a boy, but no water. However, Pi understands the necessity of water. Being deprived of it, he calls it “liquid life” when it touches his lips, quenching his thirst. Water isn’t just life blood in the book, it’s a messenger and a barrier PI must overcome to survive.
Most obviously, you need water to live. After days without water and incredibly weak, PI gets a taste of water and feels as though he “was coming back to life from the dead”. Water replenishes your will to survive by making you capable to survive. Even animals understand this as shown when discussing where Richard Parker’s name came from, the 2 big cats,