“The Haunted Beach.” (pdf, about 4,600 words)
I submitted this to a short-story contest/anthology a few months ago. It was rejected. Maybe because it was no good. Or maybe because the theme of the anthology was “optimism.”
The rules said submissions could have dark elements but needed to be optimistic overall. I thought this story just bubbled with optimism (after said “dark elements”). But you can probably see why contest judges might disagree.