What are some of Ahab's greatest weaknesses?
Ahab is unable to rationally consider his actions and their potential consequences. He is consumed by the need to have revenge upon the whale and pursues his quarry without regard to the safety of himself or his crew, with no thought for the condition of his ship, oblivious to time of day or night, weather conditions, or any other force that might have brought his pursuit to a different conclusion.
He is unable to allow any human companionship to interfere with his obsession. He takes unreasonable risks, makes outlandish demands, and moderates his behavior for no one, because he sees no value or purpose in human associations.