...risking my life and the old sub to chase a wild hair through the vast, dark ocean.This would be a jarring enough metaphor if "hare" had been spelt correctly, as a waterlogged animal would not get very far once submerged in the vast dark ocean. With the incorrect spelling of "hair", the entire sentence is nonsensical.
Later on, when we first encounter the ray of light of the title of the story, it appears thus:
...there was a gloaming light in the very far distance. Only, gloaming wasn't the right word.Indeed it wasn't; "gloaming" is not an adjective, but a noun which means "twilight", often more specifically "dusk". The narrator / the author may have meant "dim" or "gleaming".
This one will not be at the top of my ballot paper.