Hope
The easiest theme to grasp in this tragic and exhausting tale is the collective infatuation with the possibility of survival. Without that tiny shred of hope that they would reach the coast of South America, that the wind might pick up, and that the misery was worth it in the end, the sailors never would have been able to see Nantucket again.
Final Hours Before Death
As many sailors perish throughout the book, there is a large focus on the last moments of their lives and subsequently on the crew's reaction to the death. Barring Isaac Cole's manic episode, most of the men died very peacefully and left the crew in a somber, but somewhat neutral solitude. The fact of death is not a phenomenon experienced only by sea-locked sailors, but rather is something that everybody has to face in their lifetimes, so this theme is particularly relatable to any reader.
Predator/Prey Dichotomy
The book's story is always phrased in terms of the pursuer and the pursued, or better yet, the predator and the prey. When the Essex is sunk by its own prey, it is the sailors who become preyed upon and the sharks of the ocean that become the predators.
Morality
The sailors face the most extreme situations imaginable within the experience of humanity, which puts them in direct contact with the situations that most of us have only considering jokingly in a hypothetical question like in the "would you rather" game. Philbrick fills the reader in on many of the options that the men never considered, such as using the first man's body as bait so that they could catch sea-creatures to eat instead of resorting to cannibalism. But hindsight is 20/20.
Leadership
Philbrick brings in scientific models for effective disaster responses to render this tale into not only a tragedy, but also a lesson from which there is much to be learned. One example is when Pollard elects a more democratic model of leadership directly after the ship sinks, which disaster psychologists warn against for many reasons. Chase, on the other hand, often employs a healthy combination of authoritative assertion and empathy with his crew. Philbrick also discusses the role of active and passive leadership styles and the psychological change that occurred in Nantucketers when they left land, employing a 'fishy' or fierce leadership style unknown to their land contemporaries.
Available Information
One of the poorest excuses for the deaths of so many of the sailors was the lack of knowledge on the part of the captain and mates. Had they researched the readily available information about Tahiti, the Society Islands, Hawaii, or even the wind patterns of the region, they never would have had such misfortune. Nantucketers were tragically skeptical of knowledge that came from lips other than their own.
Identity
While this book cannot account for each character the way Melville could in his fictionalized account, the role of identity was huge for the main characters: Chase, Nickerson, and Pollard. When their eyes shrunk into their heads and their cheek bones protruded with the onset of their extreme thirst, they all began to look similar. They were no longer Chase, Nickerson, and Pollard, but rather, Boat Captain 2, Boat Captain 1, and Crewmember, respectively.
