The question I'm left with after reading this is “why?” Why is this story post-apocalyptic? It adds nothing to the story and bogs it down with worldbuilding that is barely fleshed out. Why have the character be a diver who recovers relics and then not have the relics play any role in the story? Half the story goes with no payoff, while the payoff for the “secrets from the past” is a very predictable twist.
All that being said, there is definitely potential. The prose is good and I do want to know more about the world. I hope the author keeps writing and improving their art. I just think they need to take more time and expand the elements of their story, making sure that each element has a reason to be there