In the book Life of Pi, what did Pi decide to do on the lifeboat to ensure his rights?

Pi intentionally provokes Richard Parker to step into Pi’s territory, at which point he blows his whistle furiously and uses the raft to make the lifeboat go broadside - and thus rock uncomfortably for Richard Parker - so that the tiger will associate his nausea with the sound of the whistle. He allows Richard Parker to recover, then repeats the process until the whistle alone is enough to make the tiger retreat.