santiago's displayed actions

Santiago moves past exhaustion and failure; his endurance is rewarded;

"I could just drift, he thought, and sleep and put a bight of line around my toe to wake me. But today is eighty-five days and I should fish the day well.

Just then, watching his lines, he saw one of the projecting green sticks dip sharply."

Santiago is tired, simply exhausted, but he utilizes all of his skills because he knows the fish is tired too.

"What I will do if he decides to go down, I don’t know. What I’ll do if he sounds and dies I don’t know. But I’ll do something. There are plenty of things I can do."