An old fisherman down on his luck, Santiago, alone, goes farther out to sea than ever before. He hooks a marlin bigger and stronger than any he has caught previously and engages in an epic struggle as the fish pulls him even farther out to sea. Defying hunger, thirst, exhaustion, and pain, he perseveres and finally reels in the marlin, only to lose it to sharks. Destroyed but not defeated, the old man arrives home with his skiff damaged. Knowing he will go out again, doing what a fisherman must do, he accepts his fate, thus rising above it.
Manolin sees Santiago as his mentor whom he meets at the end of every day to help pack up the equipment and bring him food. Manolin's parents no longer allow him to fish with Santiago because of the old man's unfortunate luck. Upon Santiago's return with the marlin's skeleton, Manolin vows to restore the old man's boat and fish with him again, convinced his presence will turn the old man's luck for the better. As a representative of youth, he guarantees Santiago's great feat will live on in the future.
The 18-foot marlin is the old man's worthy adversary. Although it has been hooked, the marlin shows no sign of defeat; instead it pulls the old man's skiff for several days and nights, taking control of the situation until exhaustion defeats it. Yet even in death, its skeleton bears witness to the magnificent struggle that took place out on the ocean.