One of the most dominant conflict in the story is individual vs. nature. Once again, it is Brian against the wilderness as he teaches Derek what survival is and then as he seeks to save Derek and himself from the harsh conditions of the natural world. Brian must struggle against lack of food, natural realities, as well as "the river." These struggles pit the individual against a state of nature. It is one that Brian navigates through. However, like his original survival experience, it takes its toll on him physically.
Another conflict that is evident is the individual against themselves. At times, Brian struggles with the realities that he faces. Issues such as if he could "dump" Derek, things would be easier or whether or not he has the strength to continue when he loses the raft would be instances where a conflict is evident in his identity. This conflict is brought on by the challenges of a survival situation. Early on in the narrative, Brian speaks of this condition to Derek, setting the tone for what will come:
You must settle. In your mind. There are some fights you can’t win, and I think this must be one of them.
The struggle between when to fight and when to know that "settling in" is the better path is reflective of the struggle within himself that Brian engages at different points.