Santiago, the Old Man, feels that a man is never alone at sea. During his journey, what animals and things has he mentioned as friends? In what way are they his friends?

Santiago measures himself through his relationship with sea creatures. The flying fish are "his principal friends on the ocean," and he considers the marlin, his "brother." The flying fish show him the way to his catch. The Marlin is majestic like he once was. The Marlin and Santiago share the struggle together, they are bonded as brothers.