The trip was carefully planned and chaperoned by the doctor. McMurphy also faced a challenge to convince Bromden to go on the trip with the rest of the patients. The movie showed an exact opposite scene involving McMurphy and the patients escaping from the hospital on a stolen bus. In my opinion, the movie left out two important characters, the chief and the doctor. The movie also included some humor when they tell the boat dock owner that they are all doctors from the mental hospital down the road. He believes them and the patients are on their way out on the water, unsupervised. The fun ends when the National Guard flies over their boat and picks them up in a helicopter. The definite changes between the book and movie are clear in the way the fishing trips are arranged. The way McMurphy stuck up for the other patients in the shower incident was a direct example of how he felt about his friends even though he knew he was committed to the hospital. This scene made an impact on me in both the book and movie.
George's character being left out of the movie was a major change. George was the reason McMurphy got in the fight with the black boys in the shower room. McMurphy's courage to stand up for George is what led to his lobotomy. The movie used a scene that included Cheswick having a fit because the nurse wouldn't give him his cigarettes. The black boys stepped in to settle Cheswick down, and that's when McMurphy walked up and punched the nurse's glass window. This resulted in the fight between him and the boys. Another change was how the book included the Chronics in almost every scene. Kesey talked about how they sat in the corner with their catheters running down the sides of their legs. In the movie, the nurse rarely mentions the Chronics, except when she needs to use them against McMurphy in the vote to watch the World Series. My theory is that the producers were trying to avoid confusing the viewers by using more characters.