Why does the author repeatedly mention fate in the story? how does this idea accentuate the story's theme?

Stephen Crane repeatedly mentions fate because the four men on the small boat are at the mercy of the ocean. They try their best to get out of their situation, but they barely manage to survive. They resent the fact that nature does not give them any respite despite their current situation and tired bodies. The idea of humans being unable to control or alter their fates helps to accentuate the story's theme of nature's indifference toward man.

Crane repeatedly mentions fate in the story because the four men on the small boat are at the mercy of the sea. They try their best to get out of their predicament, but they barely manage to survive. They resent the fact that nature doesn’t give them any respite despite their current predicament and their tired bodies. The idea of humans being unable to control or alter their fate helps to accentuate the story’s theme of nature’s indifference toward man.

(plato)

What is the passage?