As the sun sets again, Santiago ties together two oars across the stern to create more drag. Looking up into the night sky, Santiago calls the stars his friends and says, "The fish is my friend too... I have never seen or heard of such a fish. But I must kill him. I am glad we do not have to try to kill the stars" (75). After considering this, Santiago begins to feel sorry for the fish again and concludes that the people who will buy his meat at the market will not be worthy to eat of such a noble beast.
Recalling his exhaustion, Santiago decides that he must sleep some if he is to kill the marlin. He cuts up the dolphin he has caught to prevent spoiling, and eats some of it before contriving a way to sleep. Santiago wraps the line around him and leans against the bow to anchor himself, leaving his left hand on the rope to wake him if the marlin lurches.
Soon, the old man is asleep. He dreams of a school of porpoises, much like the two porpoises who arrived to comfort him in his loneliness. He also dreams of his village house, and that his right arm is asleep; though in reality, this is the part of him that is still awake, waiting to be tugged by the line. Finally he dreams of the lions of his youth on the African beach and feels happy.
Santiago is awoken by the line rushing furiously through his right hand. The marlin leaps out of the water and it is all the old man can do to hold onto the line, now cutting his hand badly and dragging him down to the bottom of the skiff. His left hand is asleep, so it is difficult to stop the line from running out with only his right hand.
Santiago finds his balance, though, and realizes that the marlin has filled the air sacks on his back and cannot go deep to die. The marlin will circle and then the endgame will begin. He cannot see the marlin but he can hear him leaping out of the water. Santiago cleans crushed dolphin meat off his face because he is afraid it will nauseate him and, vomiting, he will lose the strength he needs to fight the marlin.
At sunrise, the marlin begins a large circle. Santiago holds the line strongly, pulling it in slowly as the marlin goes round. As Santiago says, "the strain will shorten his circle each time. Perhaps in an hour I will see him. Now I must convince him and then I must kill him" (87). Santiago feels faint and worries that he will fail after this long fight. But he prays to God that he will say prayers later if only he can have the strength to defeat the fish.
Santiago continues pulling him in until the marlin catches the wire lead of the line with his spear and regains some of the line. Eventually, the marlin clears the lead and Santiago pulls back the line he lost. At the third turn, Santiago sees the fish and is amazed by its size. He readies the harpoon and pulls the line in more.
During this section, instead of concerning himself solely with his own worthiness to kill the marlin, he now concerns himself with whether the people who will buy and eat the meat of the marlin will be worthy to do so. "Are they worthy to eat him? No, of course not. There is no one worthy of eating him from the manner of his behavior and his great dignity" (75). This extension of unworthiness from the killer to consumer underscores how truly inferior Santiago thinks people are with respect to great beasts such as the marlin. He may prove his own worth by enduring his struggle, but there is no way for the people in the fish markets to prove themselves.
The theme of unity comes out in this section as well. Whereas this theme had previously taken the form of Santiago's identification with the sea and its creatures, Santiago expands the scope of his identification by including the celestial bodies as brothers. He claims fraternity with the stars on several occasions and justifies his need to sleep by considering the behavior or the moon and sun and ocean. He says, "I am as clear as the stars that are my brothers. Still I must sleep. They sleep and the moon and the sun sleep and even the ocean sleeps sometimes on certain days when there is no current and a flat calm" (77). This broader identification underscores the unity of human life with all of nature.
When he finally does fall asleep, Santiago dreams of "a vast school of porpoises that stretched for eight or ten miles and it was in the time of their mating and they would leap high into the air and return into the same hole they had made in the water when they leaped" (81). The imagery here is obviously sexual, emphasizing the feminine character of the sea which Santiago spoke about in the first section. It is mating season and the porpoises, phallic symbols par excellence, go in and out of the same hole, yonic symbol par excellence, in the ocean, already known to us as feminine.
Santiago's religion is emphasized when he prays to God to help him catch the fish; however, he prioritizes the battle with the marlin over the necessity of praying right that moment, concluding, "I'll say a hundred Our Fathers and a hundred Hail Marys. But I cannot say them now." These types of rote prayers are usually said by Catholics for penance after sinning; this commitment to say them later reflects Santiago's view of himself as sinning against the fish.
Just as Christ resisted the temptation of the devil, Santiago resists the temptation of giving in to his exhaustion as he battles the marlin. "It was a great temptation to rest in the bow and let the fish make one circle by himself without recovering any line." But he is committed to beating the fish, to proving his strength is more steadfast, thinking, "He'll be up soon and I can last. You have to last. Don't even speak of it."