Pi loses and gains several qualities as the story progresses from the time the tsimtsum sunk. During the commotion, he momentarily loses his senses and helps Richard Parker onto the lifeboat. But as soon as he realizes the danger he has put himself in, he dives into the water. After a while in the sea, he also lost hope of being rescued by a ship but anticipated coming across land. Just before going blind from dehydration, he had lost all hope and even recorded in his journal about his own death. Pi gains numerous survival skills. He makes a raft, uses the solar still to obtain fresh water from the ocean’s water, and learns how to fish, among many other techniques that enable his survival. Pi also gained courage and transitioned from being terrified by the tiger to taming it so that the two of them could coexist in the lifeboat. Throughout his encounter, Pi gained many other qualities but I think what stands out is his oscillation between losing and regaining hope, bravery and his commitment to acknowledge and worship God.
Though Pi had thought more about the nature of the world than most people his age, or indeed, than people of any age. He also had a deeper interest in religion. However, when the ship sinks, he loses two fundamental things: Pi loses his view of the world as a safe place, and he loses his previous understanding of the divine. He had led almost a charmed life, dabbling in this religion and that. Now, on the flip side, he gains immediate experience of life, the nature of the world, and the divine. He comes face to face with his deepest reality.