The Sea is an embodiment of Nature. Santiago and other fishermen see themselves as a part of it and respect this source of nourishment and potential menace, for the sea is the force beyond anyone’s control.
Marlin is the symbol of victory and reward in many senses. The parallel to Herman Melvil’s “Moby Dick” is clearly visible, but the attitude of Santiago to the marlin and the one of Captain Ahab to the white whale are quite different: Santiago sees a worthy enemy with whom he has much in common, his equal, while Ahab is blindly chasing his prize.
Santiago’s journey is also symbolic in many ways, from the fight of a man with circumstances, measurement of one’s durability and to reinterpretation of epic plots and New Testament.
When Santiago arrives to the shore, the following scene is full of religious symbols: carrying of the mast (cross bearing) and stops on his way to the shack (stations of the cross); the old man underwent his ordeal and finishes his [life] journey after completing his mission.
From Santiago’s conversation with Manolin, who is impersonating youth and hope, the reader learns that there was a search of an old man. The search went on for three days and in the end Santiago is found by Manolin in his shack, sleeping. This is a clear re-enactment of resurrection of Christ, so in spite of pitiable state of Santiago, this is his true spiritual recovery: now he is a man he used to be all his life, again.