In One Flew Over The Cuckoo's Nest, what did the fishing trip mean for each of the men?

This is a scene from the novel that is difficult to visualize, even today: patients from a mental ward getting on a charter fishing boat and spending the day out on the water.  This is part of McMurphey's struggle, almost from the moment he enters the institution, to convince the other inmates that they are still human, still men, still deserving of some of life's simple pleasures, and deserving of being out of Nurse Ratched's iron fisted control.

This act, however, is more than simple rebellion on McMurphey's part.  It is perhaps the most normal event in the entire story, and provides a stark contrast to the daily life of the inmates.  It is also a humanizing event in the eyes of the reader, where we are allowed to forget about both the mental illness and the abuse suffered by the characters in the story.