How does Santiago overcome his loneliness in The Old Man and the Sea?

Santiago is, as the title suggests, an old man.  He's been
a fisherman for his entire life, and he has learned to overcome any obstacles which face
him.  In The Old Man and the Sea, Santiago's greatest obstacle is
not his solitude, though he does have to deal with it to a greater extent than usual
because he's gone for so long.  

While he's at sea,
Santiago needs to keep himself strong in every way.  Physically, he eats the tuna he
catches, tries to rest when he can, and does his best to protect his hands and back from
the strains of the line.  Mentally, he reminds himself of the great Joe DiMaggio and his
bone spur.  Emotionally, he tries to stay focused on the present, despite his
reveries and daydreams.  This is where he fights his solitude, and he does so by talking
to the living creatures around him (the birds, the fish, the sharks) as well as
bolstering his energy by talking to himself (his hands, his back, his mind).  This is
his only defense against the solitude of being adrift in the ocean an at the whim of a
giant fish.  The greatest danger of his solitude, of course, is bringing in the fish by
himself--which he does.