Irony in The Old Man and the Sea

There is very subtle hints of irony within this novella, and it is hard to find specific passages in the book that shows irony because the evidence is all spread out in the novella(there isn't much irony anyway).But here are some passages that represent some of the irony that I found:

• "He stopped for a moment and looked back and saw in the reflection from the street light the great tail of the fish standing up well behind the skiff's stern. He saw the white naked line of his backbone and the dark mass of the head with the projecting bill and all the nakedness between."

It took him three days and so much pain to catch the fish and he had even planned out how he's going to sell it, then it just gets eaten by sharks within a day and night. This thought is just full of irony.

• "...he had gone eighty-four days now without taking a fish. In the first forty days a boy had been with him. But after forty days without a fish the boy's parents had told him that the old man was now definitely and finally salao, which was the worst form of unlucky, and the boy had gone at their orders in another boat which caught three good fish the first week."

He had gone eighty-four days without taking a fish and lost his best friend and apprentice, the boy. Then when he sets out to sea, he soon catches this eighteen feet long marlin that many fisherman might never see in their whole lifetime. But not soon after he catches the marlin, it gets completely eaten by sharks. This back and forth change from unlucky to lucky then back to unlucky is just plain ironic.