This a short story, told from the man's perspective. He's just an ordinary man, living on ordinary Earth, in "the present day" (relative to when the story was written). He is kidnapped by people claiming to be his descendants from the future, and they tell him that later in life he does something, or something happens to him, that causes some kind of problem for them. (I don't remember what the problem was, but I feel like maybe it was a reputational thing, like he made a bad name for himself and all of his eventual descendants; but maybe I'm making that up.) So they're going to stop him from doing the thing by keeping him trapped on a ship (an oceangoing ship, not a spaceship) for his whole life against his will.

The man resents his confinement, especially over something so relatively trivial, but he can't do anything about it. He spends the rest of his life on this ship with his descendants, whom he can't stand; they're shallow and ridiculous and selfish people. At the end of his life, he points out to them that they forgot to give him the opportunity to bear any children, so after all their effort to fix their problem, all they've accomplished is retroactively killing themselves. He deliberately waited to tell them until it was too late, because he resented them that much. (I think not just for kidnapping him, but for being such detestable people in general, whom he would rather not be born.)

I was asked elsewhere what happened to the descendants, and whether they vanished suddenly. I don't remember. I'm imagining the story just ends with the protagonist dying and we don't learn anything else beyond that, since he's the viewpoint character. That sounds right to me. But I'm not certain. (Edit to add: It is at least implied that the man is correct about them retroactively killing themselves, since their response is something like "Oh no!" rather than something like "Lol that's not how time travel works.")

I don't remember where I read this or what it's called. (I think I read it online, but I don't know if I read it on some website, or in the digitized version of a print book, or what.) I don't have any ideas about who the author might be. I don't remember any character names or distinguishing features. I don't remember where in the ocean the ship travels, or whether such a thing is even mentioned.

I tried several relevant tags on ISFDB (e.g. time travel, abduction, kidnapping), and several relevant tropes on TV Tropes (e.g. Ret-Gone, Set Right What Once Went Wrong, etc.), and couldn't find anything. I also posted about it on Reddit several times (mostly on r/tipofmytongue and r/whatsthatbook, and once on r/printSF), but no luck so far. This is my first time asking here.

I don't remember when I read it, but it was probably less than ten years ago. I feel like the story itself may have been older than that, though; I think it had the vibe of classic science fiction more than modern science fiction. (But I haven't exactly read a lot of modern science fiction to make a good comparison, so maybe I'm wrong and it's modern after all.)