Santiago's relationship with the sea is essentially an existential one; he exists because of the sea that provides him with food, as a fisherman, his being is defined by his relationship with the sea, and his happiness and sorrow depend upon his successes and failures on the sea. Indeed, it is the sea that is Santiago's essence and gives meaning to his life.
Because of this inextricable, but variegated connection to the sea, Santiago anthropomorphizes the sea as "La Mer" which is what people call it in Spanish when they love the ocean:
...the old man always thought of her as feminine and as something that gave or withheld great favours, and if she did wild or wicked things it was because she could not help....
Therefore, since Santiago conceives of the ocean as the source of life and meaning, the struggle of the old man with the fish in the sea becomes a metaphor for the existential struggle of man in life. Having gone eighty-four days without a catch, Santiago is viewed by the other fishermen as "unlucky," cursed, and a failure. That is, with his life threatened by starvation, Santiago's existence has little meaning. However, when he catches the great Marlin, Santiago is renewed in his manhood, his life regains its meaning and value. Because Santiago's hope and luck is renewed, even though the shark steals the meat of the fish, he can still dream of the lions and hope.
Santiago has a unique, loving relationship with the sea. He depends on his coexistence with the natural environment of the ocean to make his living. Santiago refers to the sea as la mar, which is a Spanish term of endearment. Santiago views the sea as a woman who is capable of giving or withholding rewards. He respects and reveres the sea throughout the novella and is able to interpret signs from the natural environment. Unlike the newer generation of fishermen, who rely on technology and modern techniques to catch fish, Santiago relies on the organic, traditional methods of fishing. Despite his recent bad luck, Santiago is an experienced fisherman who understands the sea and the creatures in it. He feels as if he is an intrinsic part of the ocean and recognizes his kinship with all of the sea's living creatures. The sea spiritually enriches Santiago and gives his life meaning. His role in life is connected to the sea, which is a fundamental part of his existence.