Final answer:
The question pertains to the novel 'Life of Pi' where Pi's sleep duration is contrasted with Richard Parker's ability to nap well. The duration Pi sleeps is not specified in the question and can vary throughout the book, typically characterized by stress and frequent interruptions.
Step-by-step explanation:
The question refers to the novel Life of Pi by Yann Martel, in which the character Richard Parker is mentioned as a champion napper. The blank in the sentence "While Richard Parker is a champion napper, Pi rarely sleeps longer than ____." is intentionally left for the respondent to fill in based on their knowledge of the book. Typically, in the context of the book, Pi has difficulty sleeping due to the stress of his situation, being stranded in the middle of the ocean. The actual duration can vary throughout the narrative, but generally, Pi's sleep is frequently interrupted and is not restful.