Unpopular and even actively disliked by other boys, Quackenbush sees Gene, his new assistant, as someone to whom he can finally feel superior — someone he can treat with utter contempt. For his part, Gene feels a kind of sympathy for the mean-spirited Quackenbush — a compassion that emerges from his own sense of guilty sinfulness after causing Finny's fall.
While Gene endures the crew manager's condescension and rejection, his pity evaporates when Quackenbush refers to him as a "maimed son-of-a-bitch." Clearly, Quackenbush here touches a sore point with Gene, who feels spiritually crippled for having maimed Finny. And so Gene strikes out at Quackenbush.
Gene's fury rises not only from his sense of being revealed by Quackenbush — he is, after all, morally maimed — but also out of his strong connection to Finny, who is, in fact, physically disabled from the fall. Once again, Gene instinctively identifies with Finny, transforming his guilt into shared pain.
The result of the fight between Gene and Quackenbush — a fall into the salty Naguamsett — represents a dirty dunking that contrasts sharply with the cleansing baptism of the Devon. While the earlier jump from the tree into the Devon opens Gene's eyes to a fresh vision of the world, this fall into the Naguamsett awakens him to a keener sense of his own guilt. Later, in the next chapter, Gene comes to accept his dunking as another kind of "baptism."
