Hemingway is a master of polysyndetic writing--the intentional use of repeated conjunctions (usually "and") to achieve a certain style or feel. This paragraph, describing the crucial moment in the story when Santiago first sees the fish, is a beautiful example.
The line rose slowly and steadily and then the surface of the ocean bulged ahead of the boat and the fish came out. He came out unendingly and water poured from his sides. He was bright in the sun and his head and back were dark purple and in the sun the stripes on his sides showed wide and a light lavender. His sword was as long as a baseball bat and tapered like a rapier and he rose his full length from the water and then re-entered it, smoothly, like a diver and the old man saw the great scythe-blade of his tail go under and the line commenced to race out.